. Preface
. Author Acknowledgements
. Orientation and Syllabus
. Sharing/Rating Connexions Materials
. 1. Introduction to Programming
1. Systems Development Life Cycle
2. Bloodshed Dev-C++ 5 Compiler/IDE
3. Modularization and C++ Program Layout
4. Practice 1: Introduction to Programming
6. 2. Program Planning & Design
1
2
3
4
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Program Design
Pseudocode
Test Data
Practice 2: Program Planning & Design
3. Data & Operators
. Data Types in C++
. Identifier Names
. Constants and Variables
. Data Manipulation
. Assignment Operator
. Arithmetic Operators
. Data Type Conversions
. Practice 3: Data & Operators
8. 4. Often Used Data Types
. Integer Data Type
. Floating-Point Data Type
. String Data Type
. Arithmetic Assignment Operators
. Lvalue and Rvalue
. Integer Division and Modulus
. Practice 4: Often Used Data Types
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9. 5. Integrated Development Environment
1. Integrated Development Environment
2. Standard Input and Output
3. Compiler Directives
4. Practice 5: Integrated Development Environment
10. 6. Program Control Functions
1. Pseudocode Examples for Functions
2. Hierarchy or Structure Chart
3. Program Control Functions
4. Void Data Type
5. Documentation and Making Source Code Readable
6. Practice 6: Program Control Functions
11. 7. Specific Task Functions
1. Specific Task Functions
2. Global vs Local Data Storage
3. Using a Header File for User Defined Specific Task
Functions
4. Practice 7: Specific Task Functions
12. 8. Standard Libraries
1. Standard Libraries
2. Practice 8: Standard Libraries
13. 9. Character Data, Sizeof, Typedef, Sequence
1. Character Data Type
2. Sizeof Operator
3. Typedef - An Alias
4, Sequence Operator
5. Practice 9: Character Data, Sizeof, Typedef, Sequence
14. 10. Introduction to Structured Programming
1. Structured Programming
2. Pseudocode Examples for Control Structures
3. Flowcharting
4. Practice 10: Introduction to Structured Programming
15. 11. Two Way Selection
. If Then Else
. Boolean Data Type
. Relational Operators
. Compound Statement
. Practice 11: Two Way Selection
16. 12. Multiway Selection
. Nested If Then Else
. Logical Operators
. Case Control Structure
. Branching Control Structures
5. Practice 12: Multiway Selection
17. 13. Test After Loops
. Do While Loop
. Flag Concept
. Assignment vs Equality within C++
. Repeat Until Loop
. Practice 13: Test After Loops
18. 14. Test Before Loops
1. Increment and Decrement Operators
2. While Loop
3. Practice 14: Test Before Loops
19. 15. Counting Loops
1. For Loop
2. Circular Nature of the Integer Data Type Family
3. Formatting Output
4. Nested For Loops
9. Practice 15: Counting Loops
20. 16. String Class, Unary Positive and Negative
1. String Class within C++
2. Unary Positive and Negative Operators
3. Practice 16: String Class, Unary Positive and Negative
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22.
23:
24.
25.
26.
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17. Conditional Operator and Recursion
1. Conditional Operator
2. Recursion vs Iteration
3. Practice 17: Conditional Operator and Recursion
18. Introduction to Arrays
1. Array Data Type
2. Array Index Operator
4. Practice 18: Introduction to Arrays
19. File I/O and Array Functions
. File Input and Output
. Arrays and Functions
. Loading an Array from a File
. Math Statistics with Arrays
. Practice 19: File I/O and Array Functions
20. More Array Functions
1. Finding a Specific Member of an Array
2. Sorting an Array
3. Practice 20: More Array Functions
21. More on Typedef
1. Versatile Code with Typedef
2. Practice 21: More on Typedef
22. Pointers
1. Address Operator
2. Parameter Passing by Reference
3. Pointer Data Type
4. Indirection Operator
9. Practice 22: Pointers
23. More Arrays & Compiler Directives
1. Multidimensional Arrays
2. Conditional Compilation
3. Practice 23: More Arrays & Compiler Directives
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28. 24. OOP & HPC
1. Object Oriented Programming
2. Understanding High Performance Computing
3. Practice 24: OOP & HPC
29. Review Materials
1. Review: Foundation Topics Group: 1-5
2. Review: Modular Programming Group: 6-9
3. Review: Structured Programming Group: 10-16
4. Review: Intermediate Topics Group: 17-21
5. Review: Advanced Topics Group: 22-24
30. Appendix
1. Abbreviated Precedence Chart for C++ Operators
. C++ Reserved Keywords
. ASCII Character Set
. Show Hide File Extensions
. Academic or Scholastic Dishonesty
. Successful Learning Skills
. Study Habits that Build the Brain
NOUR WN
Preface
This module introduces the Connexions online textbook/collection
"Programming Fundamentals - A Modular Structured Approach using C++"
by Kenneth Leroy Busbee.
About this Textbook/Collection
Programming Fundamentals — A Modular Structured Approach using
C++
Programming Fundamentals - A Modular Structured Approach using C++
is written by Kenneth Leroy Busbee, a faculty member at Houston
Community College in Houston, Texas. The materials used in this
textbook/collection were developed by the author and others as independent
modules for publication within the Connexions environment. Programming
fundamentals are often divided into three college courses:
Modular/Structured, Object Oriented and Data Structures. This
textbook/collection covers the first of those three courses.
On January 10, 2013 Version 1.22 was created with the modules that make
up the collection "fixed" to the their current versions. This will allow
Version 1.22 to remain static with the modules as of that date.
The collection is going to be revised with a different organization of
chapters along with updated modules to handle C++, Java and C#
programming languages. The next version of the collection will have
significant changes.
Connexions Learning Modules
The learning modules of this textbook/collection were written as
standalone modules. Students using a collection of modules as a textbook
will usually view it contents by reading the modules sequentially as
presented by the author of the collection.
However, the majority of readers of these modules will find them as a result
of an Internet search. The Connexions Project allows the author of a module
to create web links to other Connexions modules and Internet locations.
These links are shown when viewing materials on-line and are categorized
into three types: Example, Prerequisite and Supplemental. The importance
of each link is numbered from 1 to 3 by the author. When viewing the
module each links shows a three part box with yellow or white rectangles.
All three yellow means it is a strongly related link. As the yellow
decreases the importance decreases.
Students using this collection for a college course should note that all of the
Prerequisite links within the modules will be modules that student should
have already read and most of the Supplemental links will be modules that
the student will read shortly. Thus, students should use Prerequisite links for
review as needed and not be overly concerned about viewing all of the
Supplemental links at the first reading of this textbook/collection.
Conceptual Approach
The learning modules of this textbook/collection were, for the most part,
written without consideration of a specific programming language. In many
cases the C++ language is discussed as part of the explanation of the
concept. Often the examples used for C++ are exactly the same for the Java
programming language. However, some modules were written specifically
for the C++ programming language. This could not be avoided as the C++
language is used in conjunction with this textbook/collection by the author
in teaching college courses.
Bloodshed Dev-C++ 5 Compiler/IDE
This open source compiler/IDE (Integrated Development Environment) was
used to develop the demonstration source code files provided within the
modules of this textbook/collection. The compiler/IDE is presented to the
student in the second module of Chapter 1, with instructions for
downloading, installing and using the compiler/IDE. A more complete
explanation of the IDE along with demonstration source code listings with
errors is presented in first module of Chapter 5. All of the source code files
provided in this textbook/collection contain only ANSI standard C++ code
and should work on any standard C++ compiler like Microsoft Visual
Studio (which includes C++), Microsoft Visual C++ Express or Borland
C++ Builder.
Instructor Materials
Encrypted instructor materials are available in a module that is not part of
this collection. It’s title: Instructor Materials for: Programming
Fundamentals - A Modular Structured Approach using C++ is available at:
http://cnx.org/content/m34529/latest/ and the encryption code is only
available to educational institutional faculty that are considering adoption of
this collection as a textbook.
About Connexions
Connexions Modular Content
The Connexions Project http://cnx.org is part of the Open Educational
Resources (OER) movement dedicated to providing high quality learning
materials free online, free in printable PDF format, and at low cost in bound
volumes through print-on-demand publishing. This textbook is one of many
collections available to Connexions users. Each collection is composed of a
number of re-usable learning modules written in the Connexions XML
markup language. Each module may also be re-used (or 're-purposed') as
part of other collections and may be used outside of Connexions.
Re-use and Customization
The Creative Commons (CC) Attribution license applies to all Connexions
modules. Under this license, any Connexions module may be used or
modified for any purpose as long as proper attribution to the original
author(s) is maintained. Connexions' authoring tools make re-use (or re-
purposing) easy. Therefore, instructors anywhere are permitted to create
customized versions of this textbook by editing modules, deleting unneeded
modules, and adding their own supplementary modules. Connexions'
authoring tools keep track of these changes and maintain the CC license's
required attribution to the original authors. This process creates a new
collection that can be viewed online, downloaded as a single PDF file, or
ordered in any quantity by instructors and students as a low-cost printed
textbook.
Read the book online, print the PDF, or buy a copy of the book.
To browse this textbook online, visit the collection home page. You will
then have three options.
1. You may view the collection modules on-line by clicking on the "Start
>>" link, which takes you to the first module in the collection. You can
then navigate to the next module using "NEXT >>" and through the
subsequent modules by using the "<< PREVIOUS | NEXT >>" button
that is towards the upper right to move forward and backward in the
collection. You can jump to any module in the collection by clicking
on that module's title in the "TABLE OF CONTENTS" box on the left
side of the window. If these contents are hidden, make them visible by
clicking on the small triangle to the right of the "TABLE OF
CONTENTS". Chapters also have a small triangle to show or hide
contents.
2. You may obtain a PDF of the entire textbook to print or view offline
by clicking on the "Download PDF" link in the "Content Actions" box.
3. You may order a bound copy of the collection (for a reasonable
printing and shipping fee) by clicking on the "Order printed copy"
button.
Connexions PDF Conversion Problems
Buying a copy of the textbook/collection is basically sending the PDF file
to a printing service that has a contract with the Connexions project. There
are several known printing problems and the Connexions Project is aware
of them and seeking a solution. In the mean time, be aware that quirks exist
for printed PDF materials. A description of the known problems are:
1. When it converts an "Example" the PDF displays the first line of an
example properly but indents the remaining lines of the example. This
problem occurs for the printing of a book (because it prints a PDF) and
downloading either a module or a textbook/collection as a PDF.
2. Chapter numbering has been added to the on-line Table of Contents.
This will make it easier for students to quickly get to the chapter
reading materials. However this creates a "double" chapter numbering
within the textbook/collection’s PDF and custom printing formats.
3. Within C++ there are three operators that do not convert properly to
PDF format.
decrement -- which is two minus signs
insertion << which is two less than signs
extraction >> which is two greater than signs
Rating Connexion Modules
A rating feature was added during 2009 for Connexions modules. It will not
be useful until more people rate modules within the Connexions repository.
If a module is rated by several people, it can be used as a measure of
quality. Thus, your participation in rating modules is welcomed and helps
others determine the quality of the educational materials being viewed.
In order to rate modules you must have a Connexions account. Three (3)
modules have been added to the preface series of modules for this
collection. They explain why and how to create a Connexions account and
how to rate a Connexions module.
Author Acknowledgements
This module contains the author acknowledgements for the "Programming
Fundamentals - A Modular Structured Approach using C++"
textbook/collection.
I wish to acknowledge the many people who have helped me and have
encouraged me in this project.
1. Mr. Abass Alamnehe, who is a fellow faculty member at Houston
Community College. He has encouraged the use of Connexions as an
"open source" publishing concept. His comments on several modules
have led directly to the improvement of the materials in this
textbook/collection.
2. The hundreds (most likely a thousand plus) students that I have taken
programming courses that I have taught since 1984. The languages
include: COBOL, main frame IBM assembly, Intel assembly, Pascal,
"C" and "C++". They have often suggested that I write my own book
because they thought that I was explaining the subject matter better
than the author of the textbook that we were using. Little did my
students understand that directly or indirectly they aided in the
improvement of the materials from which I taught as well as
improving me as a teacher.
3. To my future students and all those that will use this
textbook/collection. They will provide suggestions for improvement as
well as being the thousand eyes identifying the hard to find typos, etc.
4. My wife, Carol, who supports me in all that I do. She has tolerated the
many hours that I have spent in concentration on developing the
modules that comprise this work. Without her support, this work
would not have happened.
Orientation and Syllabus
An orientaiton to the textbook/collection "Programming Fundamentals - A
Modular Structured Approach using C++" when used as a course.
Orientation
Textbook/Collection Layout
The approach of this course will be to take the student through a
progression of materials that will allow the student to develop the skills of
programming. The basic unit of study is a Connexions module. Several
modules are collected into a chapter. The chapters are divided into five
groups.
Group Title Chapters Modules
Pre-Chapter Items N/A 4
Foundation Topics 1-5 27
Modular Programming 6-9 17
Structured Programming 10-16 30
Intermediate Topics 17-21 17
Advanced Topics 22-24 11
Review Materials N/A 5
Appendix N/A 7
Total Modules N/A 118
Some professors using this textbook/collection might decide to eliminate
certain modules or chapters. Some may eliminate the entire Advanced
Topics group. Other professors may choose to add additional study
materials. The advantage of this textbook/collection is that it may be
adapted by professors to suit the needs of their students.
Chapter Layout
Each chapter will usually flow from:
1. One or more Connexions modules built for independent delivery.
2. A Connexions Practice module built specifically for this
textbook/collection.
As you proceed with the Connexions modules that comprise a chapter, you
should:
¢ Complete any tasks/demos that require downloading items.
e Do any exercises.
e Create 3x5 study cards for all definitions. When this material is used as
a textbook for a course the definitions are to be memorized. Confirm
this with your professor.
As you start the Practice module you will usually encounter:
e Learning Objectives
e Memory Building Activities aka MBAs Link — These could consist of
any of the following types of interactive computer activities: flash
card, crossword puzzle, seek a word, drag n drop, labeling, ordering or
sorting. When the materials are used as a textbook for a course, it is
imperative that students do a variety of repetitive activities in order to
memorize basic course material. Besides, have fun learning.
e Exercises — In addition to any exercises within the study modules that
you completed before the practice module, there will be at least one
exercise for students to complete.
e Miscellaneous Items — These will exist for some of the chapters.
e Lab Assignment — Usually, completed on one's own efforts. Review
the instructions/restrictions from your professor/teacher if using this
for a high school or college credit course.
e Problems — The intent of this activity is for students to formulate their
own answers. Thus, solutions to the problems will not be provided.
When the materials are used as a textbook for a course, the
professor/teacher may assign students to a "Study Group" or let
students form study groups to discuss their solutions with each other. If
you are using this for a high school or college credit course, verify that
you may work as team at solving the problems. This type of approved
activity is called "authorized collusion" and is not a violation of
"Academic or Scholastic Dishonesty" rules.
A professor using this textbook/collection/course will most likely have
additional lab assignments, quizzes and exams that would be used in
calculating your grade.
Connexions Module Reading List
The modules in this textbook/collection have had content reviewed and are
believed to be sufficient, thus no additional textbook is required.
However, some students desire additional references or reading. The author
has used several textbooks over the years for teaching "COSC1436 —
Programming Fundamentals I" course at Houston Community College and
at the Community College of Qatar. A reading reference list has been
prepared and includes references for the following textbooks:
1. Starting Out with C++ Early Objects, by: Tony Gaddis et. al., 7"
Edition, International Edition, ISBN: 978-0-13-137714-1
2. Starting Out with C++ Early Objects, by: Tony Gaddis et. al., 6
Edition, ISBN: 0-321-51238-3
3. Starting Out with C++ Early Objects, by: Tony Gaddis et. al., 5"
Edition, ISBN: 0-321-38348-6
4. Computer Science — A structured Approach using C++, by: Behrouz
A. Forouzan et. al., 2"! Edition, ISBN: 0-534-37480-8
These textbooks are typically available in the used textbook market at a
reasonable price. You may use any one of the three books. If you acquire
one of the above optional traditional textbooks, you may want to download
and store the following file to your storage device (disk drive or flash drive)
in an appropriate folder.
Download from Connexions:
Connexions Module Reading List _col10621.pdf
Syllabus
The syllabus for a course that is for credit will be provided by your specific
course professor. If you are using this textbook/collection for non-credit as
self-study, we have some suggestions:
. Plan regular study periods
. Review the three (3) Pre-Chapter Items modules
. Review the last four (4) modules in the Appendix
. Proceed with Chapter 1 going through all 24 chapters
. Do all of the demo programs as you encounter them
. Memorize all of the terms and definitions
. Do all lab assignments
. Prepare answers to all of the problems in the Practice modules
. At the end of every section, do the Review module
WOMAN DAU BWN FP
These is no magic way to learn about computer programming other than to
immerse yourself into regular study and study includes more than casual
reading. To help you keep track of your study, we have included a check
off list for the textbook/collection.
Check
N/A
Description
Pre-Chapter Items
Last four Appendix Items
Chapters 1 to 5
Review Materials for 1 to 5
Chapters 6 to 9
Review Materials for 6 to 9
Chapters 10 to 16
Review Materials for 10 to 16
Chapters 17 to 21
Review Materials for 17 to 21
Chapters 22 to 24
Review Materials for 22 to 24
First three Appendix Items
Total Modules
# Modules
4
4
27
17
11
118
Sharing/Rating Connexions Materials
How to share Connexions modules and collections.
Historical Rating System
At one time within Connexions there was a five (5) star rating system
provided within each Connexions module. This feature was not often used
and was discontinued.
Sharing Connexions Materials
The five (5) star rating feature was replaced with several ways for users of
Connexions materials to share with others. Available at the top and bottom
of each module or collection are:
e Google’s “+1”
e Facebook’s “Like”
e twitter’s “Tweet”
A https: enaorg'content/coll0621/latest/
i Favorites sly Sp KLB's Gene States Pg Ki} KLB's Gene Research Pg KS Quick Access Page col10621 ig OEROCW _X HCC Affiliation [-] Google Analytics @ cra Consortium |X Busbee's CNX Ting |» blog.cnxorg
Home | Content Lenses
AboutUs Help MyCNX
HGC
p TABLE OF CONTENTS ~
Preface “
Author Acknowledgements “
‘Orientation and Sytabus
Why You should Create &
Personal Connexcons Account
Cresting 3 Connexsons Account
Rating Commenons Modues /
1. Introduction to
Programming
Systems Development Life <
Cyde
Bloodshed Dev C++ S
‘Comeder IDE
Moddarizaton and C++
Program Layout
Practice 1: Introducton to
Progamming
+2. Program Planning &
Design
‘Y3. Data & Operators
Dats Types mn C++
Identofer Names
Py Addtofevowtes™ RF Adstoaiesy Giexe/Edt~ (B cowtedy
| Programming Fundamentals - A Modular Structured Approach using C++
— Collection type: Course
Course by: Kenneth beroy Bushee. (2) Emel ne author
Start »
‘Summary: Progremming Fundamentals - A Modular Structured Approach using C++ s writen by Kenneth Leroy Busbee, a facuty member at Houston Community College in
Houston, Texas. The materials used in this textbook/collection were developed by the author and others as mdependent modules for publication within the Connexions envronment. Programming
fundamental are often divided into three colege courses: Modular/Structured, Object Oriented and Data Structures. Ths textbook/colection covers the frst of those three courses,
(Order printed collecton
Institution; Houston Communty College
Course Number: COSC1436 - Programming Fundamentats I
This collection contains:
Modules by: Kenneth Leroy Susbee.
@ Internet | Protected Mode: On
Sharing Connexions Materials
Systems Development Life Cycle
An overview of the Systems Development Life Cycle.
Discussion
The Systems Development Life Cycle is the big picture of creating an
information system that handles a major task (referred to as an application).
The applications usually consist of many programs. An example would be
the Department of Defense supply system, the customer system used at
your local bank, the repair parts inventory system used by car dealerships.
There are thousands of applications that use an information system created
just to help solve a business problem.
Another example of an information system would be the "101 Computer
Games" software you might buy at any of several retail stores. This is an
entertainment application, that is we are applying the computer to do a task
(entertain you). The software actually consists of many different programs
(checkers, chess, tic tac toe, etc.) that were most likely written by several
different programmers.
Computer professionals that are in charge of creating applications often
have the job title of System Analyst. The major steps in creating an
application include the following and start at Planning step.
Maintenance Planning
Implementation Analysis
~ Design
Systems Development Life Cycle
During the Design phase the System Analyst will document the inputs,
processing and outputs of each program within the application. During the
Implementation phase programmers would be assigned to write the
specific programs using a programming language decided by the System
Analyst. Once the system of programs is tested the new application is
installed for people to use. As time goes by, things change and a specific
part or program might need repair. During the Maintenance phase, it goes
through a mini planning, analysis, design and implementation. The
programs that need modification are identified and programmers change or
repair those programs. After several years of use, the system usually
becomes obsolete. At this point a major revision of the application is done.
Thus the cycle repeats itself.
Definitions
system analyst
Computer professional in charge of creating applications.
applications
An information system or collection of programs that handles a major
task.
life cycle
Systems Development Life Cycle: Planning - Analysis - Design -
Implementation - Maintenance
implementation
The phase of a Systems Development Life Cycle where the
programmers would be assigned to write specific programs.
Bloodshed Dev-C++ 5 Compiler/IDE
An introduction to the Bloodshed Dev-C++ 5 compiler/IDE (Integrated
Development Environment) listing the advantages of using an open source
compiler that works on a flash drive. The software along with installation
instructions and a test program are included.
Introduction
Microsoft and Borland are the two reputable names within the
programming world for compilers. They sell compiler software for many
programming languages. For the C++ programming language, the
Microsoft Visual Studio which includes C++ and Borland C++ Builder are
excellent compilers. Often with textbooks or free via the internet; you can
get Microsoft’s Visual C++ Express or Borland’s Personal Edition version
of a compiler. However, installing either of these compliers can be complex.
Microsoft’s Visual Studio compiler often creates a variety of installation
problems (such as making sure the operating system and .net components
are current) thus making it difficult for students to install at home. These
compliers require you to build a project to encompass every program. Using
a commercially sold compiler that professional programmers would
consider using for project development is fine for professionals but often
confusing to beginners. Eventually, if you are going to become a
professional programmer, you will need to become familiar with the
commercially sold compilers.
We suggest that beginning students consider one of the easier to install
compiler software packages for use in a programming fundamentals course.
The best option we have found is an open source compiler/IDE (Integrated
Development Environment) named: Bloodshed Dev-C++ 5 compiler/IDE.
open source
Group development of source code for software that is made available
to the public at no cost.
Bloodshed Dev-C++ 5 compiler/IDE
Advantages: Can be installed on Windows 95/98/NT/2000/XP operating
systems. I have it installed on Windows Vista operating system, thus it can
work with slower processors and almost any Windows operating system. It
only requires about 80 MB of storage space (usually enough for the
compiler with all of its files and storage room for several of your
programs). It is very easy to install and easy to use. Does not require the
use of a "project"; thus individual source code files can be easily compiled.
Disadvantages: Would not normally be used by professional programmers,
but is sufficient for a beginning computer programming course and is a full-
featured compiler/IDE.
Unique Advantage: Can be installed and run on a flash drive, thus giving
the student the ability to work on their lab assignments on any computer
that has a USB port. This can give the student portability, being able to do
lab assignments at home, work, library, open lab, classroom, friend’s house,
etc.
portability
The ability to transport software on a flash drive and thus use it on
various machines.
Preparation before Installation
Creating the Needed Folders and Sub-Folders
You need to get the software and a C++ source code program that has been
tested and is error free. You will need about 80MB of storage space. We
suggest that you create two folders on your hard drive or flash drive
depending on which installation you choose. If on a flash drive create them
at the root level of the drive. If on your home machine, you can use the
folder area set up by the operating system for you as a user. Name them:
e Cpp_Software_Download
e Cpp_Source_Code_Files
Within the Cpp_Source_Code_Files folder, create a sub-folder named:
¢ Compiler_Test
To help you keep files organized, you will want to create other sub-folders
for storing source code files. We suggest you create at least two other sub-
folder to be used with Connexions' related modules. Within the
Cpp_Source_Code_Files, create sub-folders named:
e Demo_Programs
e Monitor_Header
folder
A named area for storage of documents or other files on a disk drive or
flash drive.
source code
Any collection of statements or declarations written in some human-
readable computer programming language.
Getting the Software
The full version of the software is named: Dev-C++ 5.0 beta 9.2 (4.9.9.2)
(9.0 MB) with Mingw/GCC 3.4.2 You can either download it from
Bloodshed or download the version as of 12/8/2008 that is stored on the
Connexions web site. Store it in the Cpp_Software_Download folder you
created. The software is approximately 9.1 MB and will take several
minutes to download if you are using a dial-up modem connection.
Note:The software has not significantly changed since 2007 and the
Connexions version will be sufficient for most users. The Bloodshed link
requires some additional navigation to get to the software download. Thus,
because it is significantly easier, we recommend that you download the
software from the Connections web site.
Link to Bloodshed: http://www.bloodshed.net/dev/devcpp.html
Download from Connexions: devcpp-4.9.9.2_ setup.exe
Getting a C++ Source Code File
Listed below is a C++ source code file titled: Compiler_Test.cpp It has been
prepared for Connexions web delivery. Download and store it in the
Compiler_Test sub-folder you created. You may need to right click on the
link and select "Save Target As" in order to download the file.
Download from Connexions: Compiler _Test.cpp
Installation Instructions for Bloodshed Dev-C++ 5
compiler/IDE
The Version 5 which is well tested (don’t let the beta release scare you) and
should work on a variety of machines and various Microsoft Operating
systems including Windows 98, Windows 2000, Windows XP and
Windows Vista. Below are installation instructions for installing it on a
machine or installing it on a flash drive. We don’t suggest trying to switch
between the machine drive and flash drive. If it is installed on the machine
drive and you try installing it on a flash drive, it creates problems and will
not work perperly. Either install it on the flash drive to gain your portability
or install it on your machine.
Computer Installation Instructions
1. Navigate to the Cpp_Software_Download folder and run the devcpp-
4.9.9.2_setup.exe software by double cliking on the filename.
2. Use common sense and answer the installation prompts. NOTE THE
FOLLOWING TWO ITEMS:
3. When it gets to the "Choose Install Location" use the default software
location of: C:\Dev-Cpp\ (or select the location you want to store the
installed program but use the default unless you are familiar with
installing software).
4. When it asks: "Do you want to install Dev C++ for all users on this
computer?" answer "Yes".
5. After it installs, it will ask some "first time configuration" questions.
Again, use common sense and answer the questions. NOTE THE
FOLLOWING ITEM:
6. Answer "No" to the retrieve information from header files.
7. It will start your compiler/IDE with a "Tip of the day". We suggest you
check the box in the lower left and select "Close".
8. Close your compiler/IDE by using the normal red "X" box. We want to
show you how to start your compiller normally.
9. You start your compiler software similar to starting any software
loaded on your machine ("Start" then "All Programs" then "Bloodshed
Dev-C++" then "Dev-C++").
10. On the menus at the top — Select "File" then "Open project or file" then
navigate to where your source code file (Compiler_Test.cpp) is stored
on your hard drive. See the suggested folder name above. Select the
source code file and open it.
11. You should see the source code listing. Press F9 key or select the
"Execute" then "Compile & Run" from the menus at the top. A black
screen box should appear and you answer questions appropriately to
run the program. When you are done running your program the black
screen box goes away.
Flash Drive Installation Instructions
1. Navigate to the Cpp_Software_Download folder and run the devcpp-
4.9.9.2_setup.exe software by double cliking on the filename.
2. Use common sense and answer the installation prompts. NOTE THE
FOLLOWING TWO ITEMS:
3. When it gets to the "Choose Install Location" you can see that the
default software location of: C:\Dev-Cpp\ however, it needs to be
changed. Change the "Destination Directory" by selecting changing
the default software location from: C:\Dev-Cpp\ to DriveLetter:\Dev-
10.
Tt.
Cpp\ (where the DriveLetter is the drive that represents your flash
drive).
. When it asks: "Do you want to install Dev C++ for all users on this
computer?" answer "No".
. After it installs, it will ask some "first time configuration" questions.
Again, use common sense and answer the questions. NOTE THE
FOLLOWING ITEM:
. Answer "No" to the retrieve information from header files.
. It will start your compiler/IDE with a "Tip of the day". We suggest you
check the box in the lower left and select "Close".
. Close your compiler/IDE by using the normal red "X" box. We want to
show you how to start your compiller normally.
. To start your compiler software you navigate to the "Dev-Cpp" folder
on your flash drive and select the "devcpp.exe" application. NOTE:
When using the flash drive you should not try starting the compiler by
double clicking on a C++ source code file. This method works on a
machine installation but does not work on a flash drive installation.
On the menus at the top — Select "File" then "Open project or file" then
navigate to where your source code file (Compiler_Test.cpp) is stored
on your flash drive. See the suggested folder name above. Select the
source code file and open it.
You should see the source code listing. Press F9 key or select the
"Execute" then "Compile & Run" from the menus at the top. A black
screen box should appear and you answer questions appropriately to
run the program. When you are done running your program the black
screen box goes away.
Modularization and C++ Program Layout
An introduction of the concepts of modular programming with a simple
example of program control and specific task functions using a C++ source
code listing. The general layout of a C++ program is described.
Concept of Modularization
One of the most important concepts of programming is the ability to group
some lines of code into a unit that can be included in our program. The
original wording for this was a sub-program. Other names include: macro,
sub-routine, procedure, module and function. We are going to use the term
function for that is what they are called in the two predominant
programming languages of today: C++ and Java. Functions are important
because they allow us to take large complicated programs and to divide
them into smaller manageable pieces. Because the function is a smaller
piece of the overall program, we can concentrate on what we want it to do
and test it to make sure it works properly. Generally functions fall into two
categories:
1. Program Control - Functions used to simply sub divide and control
the program. These functions are unique to the program being written.
Other programs may use similar functions maybe even functions with
the same name, but the content of the functions are almost always very
different.
2. Specific Task - Functions designed to be used with several programs.
These functions perform a specific task and thus are useable in many
different programs because the other programs also need to do the
specific task. Specific task functions are sometimes referred to as
building blocks. Because they are already coded and tested, we can use
them with confidence to more efficiently write a large program.
The main program must establish the existence of functions used in that
program. Depending on the programming language, there is a formal way
to:
1. define a function (it's definition or the code it will execute)
2. call a function
3. declare a function (a prototype is a declaration to a complier)
Program Control functions normally do not communicate information to
each other but use a common area for variable storage. Specific Task
functions are constructed so that data can be communicated between the
calling program piece (which is usually another function) and the function
being called. This ability to communicate data is what allows us to build a
specific task function that may be used in many programs. The rules for
how the data is communicated in and out of a function vary greatly by
programming language, but the concept is the same. The data items passed
(or communicated) are called parameters. Thus the wording: parameter
passing. The four data communication options include:
1. no communication in with no communication out
2. some communication in with no communication out
3. some communication in with some communication out
4. no communication in with some communication out
Introduction of Functions within C++
We are going to consider a simple program that might be used for testing a
compiler to make sure that it is installed correctly.
Example:
Compiler_Test.cpp source code
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// Filename: Compiler_Test.cpp
// Purpose: Average the ages of two people
// Author: Ken Busbee; © Kenneth Leroy Busbee
// Date: Jan 5, 2009
// Comment: Main idea is to be able to
// debug and run a program on your
compiler.
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void pause(void);
// Nariables
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int age2,
double answer;
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cin >> age2;
// Process
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cout << answer;
pause();
return 0;
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This program has two functions, one from each of our categories. The
technical layout of functions are the same, it is our distinction that creates
the two categories based on how a function is being implemented.
Program Control Function
The main program piece in C++ program is a special function with the
identifier name of main. The special or uniqueness of main as a function is
that this is where the program starts executing code and this is where it
usually stops executing code. It is usually the first function defined in a
program and appears after the area used for includes, other technical items,
declaration of prototypes, the listing of global constants and variables and
any other items generally needed by the program. The code to define the
function main is provided; however, it is not prototyped or usually called
like other functions within a program. In this simple example, there are no
other program control functions.
Specific Task Function
We often have the need to perform a specific task that might be used in
many programs. In the Compile_Test.cpp source code above we have such
a task that is used to stop the execution of the code until the user hits the
enter key. The functions name is: pause. This function is not
communicating any information between the calling function and itself,
thus the use of the data type void.
Example:
general layout of a function
<return value data type> function identifier
name(<data type> <identifier name for input
value>)
{
lines of code;
return <value>;
i
There is no semi-colon after the first line. Semi-colons are used at the end
of a statement in C++, but not on the first line when defining a function.
Functions have a set of braces {} used for identifying a group or block of
statements or lines of code. There are normally several lines of code within
a function. Lines of code containing the instructions end in a semi-colon.
Can you identify the definition of the pause function in the above program
example? The pause function definition is after the function main. Though
not technically required, most programs list all functions (program control
or specific task) after the function main.
Let's identify the location where the function pause is called. The calling
function is the function main and it towards the end of the function. The
line looks like:
pause();
When you call a function you use its identifier name and a set of
parentheses. You place any data items you are passing inside the
parentheses, and in our example there are none. A semi-colon ends the
statement or line of code. After our program is compiled and running, the
lines of code in the function main are executed and when it gets to the
calling of the pause function, the control of the program moves to the pause
function and starts executing the lines of code in the pause function. When
it’s done with the lines of code, it will return to the place in the program that
called it (in our example the function main) and continue with the code in
that function.
Once we know how to define a function and how to call a function, we
usually will need to know how to declare a function to the compiler (called
a prototype). Because of normal computer programming industry standards,
programmers usually list the function main first with other functions
defined after it. Then somewhere in the function main, we will call a
function. When we convert our source code program to an executable
version for running on our computer, the first step of the process is
compiling. The compiler program demands to know what the
communication will be between two functions when a function is called. It
will know the communication (what going in and out as parameters) if the
function being called has been defined. But, we have not defined that
function yet; it is defined after the function main. To solve this problem, we
show the compiler a prototype of what the function will look like (at least
the communication features of the function) when we define it.
void pause(void);
This line of code looks exactly like the first line in our function definition
with one important addition of a semi-colon. Prototypes (or declarations to
the compiler of the communications of a function not yet defined) are
placed near the top of the program before the function main. Summary
concept: If you call a function before it is defined you must prototype it
before it is called. Looking at our list of the three things you do in
conjunction with a function in the order that they normally appear in a
program, there is a formal way to:
1. declare a function (a prototype is a communications declaration to a
complier)
2. call a function
3. define a function
C++ Program Layout
From the above example, you can see that 2/3 of the program is the two
functions. Most C++ programs have several items before the function main.
As in the example, they often are:
1. Documentation — Most programs have a comment area at the start of
the program with a variety of comments pertinent to the program. Any
line starting with two slashes // is a comment and the compiler
software disregards everything from the // to the end of the line.
2. #include<iostream> — This line of code inserts a file into the source
code. The file contains necessary code to be able to do simple input
and output.
3. using namespace std — The C++ compiler has an area where it keeps
the identifier names used in a program organized and it is called a
namespace. There is a namespace created in conjunction with the
iostream file called: std. This line informs the compiler to use the
namespace std where the identifier names in the iostream are
established.
4. Function prototypes have already been explained.
5. We need some variables (storage areas) for this program to work. They
are defined next.
Definitions
modularization
The ability to group some lines of code into a unit that can be included
in our program.
function
What modules are called in the two predominant programming
languages of today: C++ and Java.
program control
Functions used to simply sub divide and control the program.
specific task
Functions designed to be used with several programs.
parameter passing
How the data is communicated in to and out of a function.
identifier name
The name given by the programmer to identify a function or other
program items such as variables.
function prototype
A function's communications declaration to a complier.
function call
A function's using or invoking of another function.
function definition
The code that defines what a function does.
braces
Used to identify a block of code in C++.
Practice 1: Introduction to Programming
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Install the Bloodshed Dev-C++ 5 compiler
3. Make minor modifications to an existing program
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Beginning programmers participate in all phases of the Systems
Development Life Cycle.
2. The Bloodshed Dev-C++ 5 compiler/IDE is the preferred
compiler for this textbook/collection, however any C++ compiler
will work.
3. Most compilers can be installed on a flash drive.
4. In addition to function as the name of a sub-program, the
computer industry also uses macro, procedure and module.
5. Generally functions fall into two categories: Program Control and
Specific Task.
Solution:
Answers:
1. false
2. true
3. false
4. true
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 01 Files
Within the Chapter 1 Connexions modules you were given directions on
how to install the Bloodshed Dev-C++ 5 compiler/IDE and to test your
installation with the Compiler_Test.cpp source code file. If you have not
done this, return to the Connexions materials and complete this task.
In the compiler installation directions you were asked to make a folder
named: Cpp_Source_Code_Files. All of your lab assignments in this course
assume you have that folder on the same drive as your compiler (either
drive C: your hard disk drive, or on a flash drive). If you don’t have that
folder, go create it now.
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_01 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Compiler _Test.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Navigate to your sub-folder: Chapter_01 and rename the
Compiler_Test.cpp source code file to: Lab_01.cpp
e If you are having problems seeing the file extensions, visit the “Show
Hide File Extensions” instructions within the Appendix.
e Start your compiler and open the source code file. Carefully make the
following modifications:
e Change the comments at the top, specifically:
e The filename should be: Lab_01.cpp
e Purpose should be: Average the weight of three people
e Remove the next 2 lines of comment talking about the main idea
e Author: put your name and erase my name and copyright
e Date: Put today's date
¢ Remove the next 3 lines of comment dealing with licensing (don't
erase the asterisk line)
Note:During the rest of the course you will often use a source code file
provided by the instructor as your starting point for a new lab assignment.
Sometimes you will use a source code file that you have created as your
Starting point for a new lab assignment. Either way, you should modify the
comments area as appropriate to include at a minimum the four lines of
information (filename, purpose, author and date) as established in this lab
assignment.
e We are now going to make simple modifications to this program so
that it is able to average the weight of three people. Do the
following:
e Within the variables area, change the variable names for agel and age2
to weight1 and weight2. Add another variable of integer data type with
the identifier name of weight3.
e The input area has two prompts and requests for data from the user.
They are paired up — a prompt and getting data from the keyboard. We
need to modify the prompt to ask for weight instead of age. We need to
change the variable name from age1 to weight1. Do this for the second
pair that prompts and gets the second data item. Create a third pair that
prompts and gets the third data item.
e The process area has only one line of code and we need to make
changes that add the weight3 and divides by 3.0 instead of 2.0. The
code should look like this:
¢ answer = (weight1 + weight2 + weight3) / 3.0;
e The output area needs the text modified from ages to weights.
¢ Build (compile and run) your program. You have successfully written
this program if when it run and you put in the three weights; it tells
you the correct average.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 01a — Instructions
List the steps of the Systems Development Life Cycle and indicate which
step you are likely to work in as a new computer professional.
Program Design
An introduction to the computer program design process.
Topic Introduction
Program Design consists of the steps a programmer should do before they
start coding the program in a specific language. These steps when properly
documented will make the completed program easier for other programmers
to maintain in the future. There are three broad areas of activity:
e Understanding the Program
e Using Design Tools to Create a Model
¢ Develop Test Data
Understanding the Program
If you are working on a project as a one of many programmers, the system
analyst may have created a variety of documentation items that will help
you understand what the program is to do. These could include screen
layouts, narrative descriptions, documentation showing the processing
steps, etc. If you are not on a project and you are creating a simple program
you might be given only a simple description of the purpose of the program.
Understanding the purpose of a program usually involves understanding
it's:
e Inputs
e Processing
¢ Outputs
This IPO approach works very well for beginning programmers.
Sometimes, it might help to visualize the programming running on the
computer. You can imagine what the monitor will look like, what the user
must enter on the keyboard and what processing or manipulations will be
done.
Using Design Tools to Create a Model
At first you will not need a hierarchy chart because your first programs will
not be complex. But as they grow and become more complex, you will
divide your program into several modules (or functions).
The first modeling tool you will usually learn is pseudocode. You will
document the logic or algorithm of each function in your program. At first,
you will have only one function, and thus your pseudocode will follow
closely the IPO approach above.
There are several methods or tools for planning the logic of a program.
They include: flowcharting, hierarchy or structure charts, pseudocode,
HIPO, Nassi-Schneiderman charts, Warnier-Orr diagrams, etc.
Programmers are expected to be able to understand and do flowcharting and
pseudocode. These methods of developing the model of a program are
usually taught in most computer courses. Several standards exist for
flowcharting and pseudocode and most are very similar to each other.
However, most companies have their own documentation standards and
styles. Programmers are expected to be able to quickly adapt to any
flowcharting or pseudocode standards for the company at which they work.
The others methods that are less universal require some training which is
generally provided by the employer that chooses to use them.
Later in your programming career, you will learn about using applications
software that helps create an information system and/or programs. This type
of software is called Computer-aided Software Engineering.
Understanding the logic and planning the algorithm on paper before you
Start to code is very important concept. Many students develop poor habits
and skipping this step is one of them.
Develop Test Data
Test data consists of the user providing some input values and predicting
the outputs. This can be quite easy for a simple program and the test data
can be used to check the model to see if it produces the correct results.
Definitions
IPO
Inputs - Processing - Outputs
pseudocode
English-like statements used to convey the steps of an algorithm or
function.
test data
Providing input values and predicting the outputs.
Pseudocode
An introduction to pseudocode with a simple example.
Overview
Pseudocode is one method of designing or planning a program. Pseudo
means false, thus pseudocode means false code. A better translation would
be the word fake or imitation. Pseudocode is fake (not the real thing). It
looks like (imitates) real code but it is NOT real code. It uses English
statements to describe what a program is to accomplish. It is fake because
no complier exists that will translate the pseudocode to any machine
language. Pseudocode is used for documenting the program or module
design (also known as the algorithm).
The following outline of a simple program illustrates pseudocode. We want
to be able to enter the ages of two people and have the computer calculate
their average age and display the answer.
Example:
Outline using Pseudocode
Input
display a message asking the user to enter the
first age
get the first age from the keyboard
display a message asking the user to enter the
second age
get the second age from the keyboard
Processing
calculate the answer by adding the two ages
together and dividing by two
Output
display the answer on the screen
pause so the user can see the answer
After developing the program design, we use the pseudocode to write code
in a language (like Pascal, COBOL, FORTRAN, "C", " C++", etc.) where
you must follow the rules of the language (syntax) in order to code the logic
or algorithm presented in the pseudocode. Pseudocode usually does not
include other items produced during programming design such as identifier
lists for variables or test data.
There are other methods for planning and documenting the logic for a
program. One method is HIPO. It stands for Hierarchy plus Input Process
Output and was developed by IBM in the 1960s. It involved using a
hierarchy (or structure) chart to show the relationship of the sub-routines (or
functions) in a program. Each sub-routine had an IPO piece. Since the
above problem/task was simple, we did not need to use multiple sub-
routines, thus we did not produce a hierarchy chart. We did incorporate the
IPO part of the concept for the pseudocode outline.
Definitions
pseudo
Means false and includes the concepts of fake or imitation.
Test Data
An explanation of test data with an example developed from a simple
program documented with pseudocode.
Overview
Test data consists of the user providing some input values and predicting the
outputs. This can be quite easy for a simple program and the test data can
be used twice.
1. to check the model to see if it produces the correct results (model
checking)
2. to check the coded program to see if it produces the correct results
(code checking)
Test data is developed by using the algorithm of the program. This
algorithm is usually documented during the program design with either
flowcharting or pseudocode. Here is the pseudocode in outline form
describing the inputs, processing and outputs for a program used for
painting rectangular buildings.
Example:
Pseudocode using an IPO Outline for Painting a Rectangular Building
Input
display a message asking user for the length of
the building
get the length from the keyboard
display a message asking user for the width of
the building
get the width from the keyboard
display a message asking user for the height of
the building
get the height from the keyboard
display a message asking user for the price per
gallon of paint
get the price per gallon of paint from the
keyboard
display a message asking user for the sq ft
coverage of a gallon of paint
get the sq ft coverage of a gallon of paint from
the keyboard
Processing
calculate the total area of the building by:
multiplying the length by height by 2
then multiply the width by height by 2
then add the two results together
calculate the number of gallons of paint needed
by:
dividing the total area by the coverage per
gallon
then round up to the next whole gallon
calculate the total cost of the paint by:
multiplying the total gallons needed by the
price of one gallon of paint
Output
display the number of gallons needed on the
monitor
display the total cost of the paint on the
monitor
pause so the user can see the answer
Creating Test Data and Model Checking
Test data is used to verify that the inputs, processing and outputs are
working correctly. As test data is initially developed it can verify that the
documented algorithm (pseudocode in the example we are doing) is correct.
It helps us understand and even visualize the inputs, processing and outputs
of the program.
Inputs: My building is 100 feet long by 40 feet wide and 10 feet in height
and I selected paint costing $28.49 per gallon that will cover 250 square
feet per gallon. We should verify that the pseudocode is prompting the user
for this data.
Processing: Using my solar powered hand held calculator, I can calculate
(or predict) the total area would be: (100 x 10 x 2 plus 40 x 10 x 2) or 2,800
sq ft. The total gallons of paint would be: (2800 / 250) or 11.2 gallons. But
rounded up, I would need twelve (12) gallons of paint. The total cost would
be: (28.49 times 12) or $341.88. We should verify that the pseudocode is
performing the correct calculations.
Output: Only the significant information (number of gallons to buy and the
total cost) are displayed for the user to see. We should verify that the
appropriate information is being displayed.
Testing the Coded Program — Code Checking
The test data can be developed and used to test the algorithm that is
documented (in our case our pseudocode) during the program design phase.
Once the program is code with compiler and linker errors resolved, the
programmer gets to play user and should test the program using the test data
developed. When you run your program, how will you know that it is
working properly? Did you properly plan your logic to accomplish your
purpose? Even if your plan was correct, did it get converted correctly
(coded) into the chosen programming language (in our case C++)? The
answer (or solution) to all of these questions is our test data.
By developing test data we are predicting what the results should be, thus
we can verify that our program is working properly. When we run the
program we would enter the input values used in our test data. Hopefully
the program will output the predicted values. If not then our problem could
be any of the following:
1. The plan (IPO outline or other item) could be wrong
2. The conversion of the plan to code might be wrong
3. The test data results were calculated wrong
Resolving problems of this nature can be the most difficult problems a
programmer encounters. You must review each of the above to determine
where the error is lies. Fix the error and re-test your program.
Definitions
model checking
Using test data to check the design model (usually done in
pseudocode).
code checking
Using test data to check the coded program in a specific language (like
C++).
Practice 2: Program Planning & Design
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Create a pseudocode document for a programming problem
3. Create a test data document for a programming problem
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Coding the program in a language like C++ is the first task of
planning. You plan as you code.
2. Pseudocode is the only commonly used planning tool.
3. Test data is developed for testing the program once it is code into
a language like C++.
4. The word pseudo means false and includes the concepts of fake or
imitation.
5. Many programmers pick up the bad habit of not completing the
planning step before starting to code the program.
Solution:
Answers:
1. false
2. false
3. false
4. true
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 02 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_02 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Solution Lab 01 Pseudocode.txt
Download from Connexions: Solution Lab 01 Test Data.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Navigate to your sub-folder: Chapter_02 and print the:
Solution_Lab_01_Pseudocode.txt and the:
Solution_Lab_01_Test_Data.txt files. Review the printouts in
conjunction with your Lab 01 source code file. Note: In Lab 01 we
gave you Step by step directions for modifying the Compiler_Test.cpp
source code file into the Lab_01.cpp source code file. I could have
given you the pseudocode and test data files, but you had not received
any instructions about them. Now, after having studied the Chapter 2
materials, these files should make sense.
¢ Make copies of the: Solution_Lab_01_Pseudocode.txt and
Solution_Lab_01_Test_Data.txt and rename them:
Lab_02_Pseudocode.txt and Lab_02_Test_Data.txt
e Here is the problem. Your local bank has many customers who save
their change and periodically bring it in for deposit. The customers
have sorted the coins (pennies, nickels, dimes and quarters — forget
half dollars and dollar coins) and know how many (an integer data
type) of each value they have but have evolved (or their environment
has made them lazy). They have lost their ability to do simple
arithmetic. They can’t seem to determine the total value of all of the
coins without a calculator (or computer). Write a program to interact
with the customers and to determine and report the total value of their
coins.
¢ No! No! No! We are not going to write a program (create source code)
using the C++ programming language. We are going to design a plan
for a program using pseudocode as our model. Additionally, we need
to develop some test data for use in testing our model.
e Start your text editor (Microsoft Notepad. Set the font on Notepad to:
Courier 12 font because Courier uses the same amount of space
horizontally for each letter. It will make the information in the files
show as it should be seen. Open your Lab 02 pseudocode text file.
Change all items as needed to be able to solve the above problem.
NOTE: You may use any application software that will let you open,
modify and save ASCII text files. You may even use the Bloodshed
Dev-C++ 5 compiler/IDE software to view, modify and save ASCII
text files; after all, our source code files are ASCII text files with a
special extension of .cpp
¢ Open your Lab 02 test data text file. Modify the text file as
appropriate. Use your test data and step through your pseudocode.
Does everything seem to work? Have you missed something?
e When you are satisfied that you have your program plan and test data
completed, close your text files. That’s right, I said, "Save and close
your text files." Files should be properly closed before being used by
other software and this includes the Operating System software that
moves, copies and renames files.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 02a — Instructions
Create simple IPO pseudocode to solve the following:
Problem: I have a friend who is visiting from Europe and he does not
understand exactly how much gas he is buying for his car. We need to write
a program that allows him to enter the gallons of gas and convert it to liters
(metric system). NOTE: One US gallon equals 3.7854 liters.
Problem 02b — Instructions
Create test data for the following:
Problem: A major restaurant sends a chef to purchase fruits and vegetables
every day. Upon returning to the store the chef must enter two pieces of
data for each item he purchased. The quantity (Example: 2 cases) and the
price he paid (Example: $4.67). The program has a list of 20 items and after
the chef enters the information, the program provides a total for the
purchases for that day. You need to prepare test data for five (5) items:
apples, oranges, bananas, lettuce and tomatoes.
Data Types in C++
An introduction to data types within the C++ programming language.
General Discussion
Our interactions (inputs and outputs) of a program are treated in many
languages as a stream of bytes. These bytes represent data that can be
interpreted as representing values that we understand. Additionally, within a
program we process this data in various ways such as adding them up or
sorting them. This data comes in different forms. Examples include:
yourname which is a string of characters; your age which is usually an
integer; or the amount of money in your pocket which is usually a value
measured in dollars and cents (something with a fractional part). A major
part of understanding how to design and code programs in centered in
understanding the types of data that we want to manipulate and how to
manipulate that data.
"A type defines a set of values and a set of operations that can be applied
on those values. The set of values for each type is known as the domain for
that type."[footnote] The four major families of data include:
Behrouz A. Forouzan and Richard F. Gilberg, Computer Science A
Structured Approach using C++ Second Edition (United States of America:
Thompson — Brooks/Cole, 2004) 33.
e Nothing
e Integer
e Floating-point
e Complex
The C++ programming language identifies five data types as standard data
types:
e Void
e Boolean
e Character
e Integer
e Floating-point
The standard data types and the complex data types within C++ have a
series of attributes, which include:
e C++ Reserved or Key Word
e Domain — the allowed values
e Signage — do they allow negative numbers or only positive numbers
e Meaning — i.e. What do they represent
e Rules of Definition — What special characters indicate the data type
e Size —in terms of the number of bytes of storage used in the memory
e Operations Allowed — i.e. Which operators can I use on the data type
Placing some of the above into a summary table, we get:
Famil Data Reserved Wepresente Standard
y Type Word P Type
Nothing a void No data Yes
Logical
Integer Boolean bool true and Yes
false
Integer Character char Sing Yes
characters
Integer Integer int thea Yes
Floating Floating fant Fractional Vee
Point Point numbers
Complex String string A sequence No
(sting them
along) of
characters
A
collection
Complex Array N/A of elements No
of the same
data type
A value
that points
toa
Complex Pointer N/A ae No
address)
within the
data area
The five standard data types usually exist in most programming languages
and act or behave similarly from language to language. Most courses of
study for a programming course or language will explain the standard data
types first. After they are learned, the complex data types are introduced.
The Boolean, character and integer data types are identified as belonging to
the Integer Family. These data types are all represented by integer numbers
and thus act or behave similarly.
Definitions
data type
Defines a set of values and a set of operations that can be applied on
those values.
data type families
1) Nothing 2) Integer 3) Floating-Point 4) Complex
domain
The set of allowed values for a data type.
integer
A data type representing whole numbers.
floating point
A data type representing numbers with fractional parts.
Identifier Names
An explanation of identifier names including some common rules for the
C++ programming language.
Overview
Within programming a variety of items are given descriptive names to make
the code more meaningful to us as humans. These names are called
"Identifier Names". Constants, variables, type definitions, functions, etc.
when declared or defined are identified by a name. These names follow a
set of rules that are imposed by:
1. the language's technical limitations
2. good programming practices
3. common industry standards for the language
Technical to Language
e Use only allowable characters (for C++ the first character alphabetic or
underscore, can continue with alphanumeric or underscore)
e Can't use reserved words
e Length limit
These attributes vary from one programming language to another. The
allowable characters and reserved words will be different. The length limit
refers to how many characters are allowed in an identifier name and often is
compiler dependent and may vary from compiler to compiler for the same
language. However, all programming languages have these three technical
rules.
Good Programming Techniques
e¢ Meaningful
e Be case consistent
Meaningful identifier names make your code easier for another to
Wat
understand. After all what does "p" mean? Is it pi, price, pennies, etc. Thus
do not use cryptic (look it up in the dictionary) identifier names.
Some programming languages treat upper and lower case letters used in
identifier names as the same. Thus: pig and Pig are treated as the same
identifier name. Unknown to you the programmer, the compiler usually
forces all identifier names to upper case. Thus: pig and Pig both get
changed to PIG. However not all programming languages act this way.
Some will treat upper and lower case letters as being different things. Thus:
pig and Pig are two different identifier names. If you declare it as pig and
then reference it in your code later as Pig — you get a compiler error. To
avoid the problem altogether, we teach students to be case consistent. Use
an identifier name only once and spell it (upper and lower case) the same
way within your program.
Industry Rules
¢ Do not start with underscore (used for technical programming)
e variables in all lower case
¢ CONSTANTS IN ALL UPPER CASE
These rules are decided by the industry (those who are using the
programming language). The above rules were commonly used within the
"C" programming language and have to large degree carried over to C++.
Definitions
reserved word
Words that cannot be used by the programmer as identifier names
because they already have a specific meaning within the programming
language.
Constants and Variables
An introductory explanation of constants and variables with examples and
how to define them within the C++ programming language.
Understanding Constants
Various textbooks describe constants using different terminology. Added to
the complexity are the explanations from various industry professionals will
vary greatly. Let's see if we can clear it up.
A constant is a data item whose value cannot change during the program's
execution. Thus, as its name implies — their value is constant.
A variable is a data item whose value can change during the program's
execution. Thus, as its name implies — their value can vary.
Constants are used in three ways within C++. They are:
1. literal constant
2. defined constant
3. Memory constant
A literal constant is a value you type into your program wherever it is
needed. Examples include the constants used for initializing a variable and
constants used in lines of code:
Example:
Literal Constants
int age = 21;
char grade = 'A';
float money = 12.34;
pOOL ‘“ficn false;
cout << "\nStudents love computers";
age = 57;
Additionally, we have learned how to recognize the data types of literal
constants. Single quotes for char, double quotes for string, number without
a decimal point for integer, number with a decimal point belongs to the
floating-point family, and Boolean can use the reserved words of true or
false.
In addition to literal constants, most text books refer to either symbolic
constants or named constants but these two refer to the same concept. A
symbolic constant is represented by a name similar to how we name
variables. Let's say it backwards; the identifier name is the symbol that
represents the data item. Within C++ identifier names have some rules. One
of the rules says those names should be meaningful. Another rule about
using ALL CAPS FOR CONSTANTS is an industry rule. There are two
ways to create symbolic or named constants:
#define PI 3.14159
Called a defined constant because it uses a textual substitution method
controlled by the compiler pre-processor command word "define".
const double PI = 3.14159;
The second one is called sometimes called constant variable but that name
is contradictory all by itself. How can it be constant and vary at the same
time? The better name for the second one is a memory constant because
they have a "specific storage location in memory”.
Defining Constants and Variables
In the above examples we see how to define both variables and constants
along with giving them an initial value. Memory constants must be assigned
a value when they are defined. But variables do not have to be assigned
initial values.
int height;
float value_coins;
Variables once defined may be assigned a value within the instructions of
the program.
height = 72;
Valueoeoins = 2 * 0.25 4.3 7-02.05:
Definitions
constant
A data item whose value cannot change during the program's
execution.
variable
A data item whose value can change during the program's execution.
Data Manipulation
An introduction to expressions with definitions, an example and an
explanation of precedence.
Introduction
Single values by themselves are important; however we need a method of
manipulating values (processing data). Scientists wanted an accurate
machine for manipulating values. They wanted a machine to process
numbers or calculate answers (that is compute the answer). Prior to 1950,
dictionaries listed the definition of computers as " humans that do
computations". Thus, all of the terminology for describing data
manipulation is math oriented. Additionally, the two fundamental data type
families (the integer family and floating-point family) consist entirely of
number values.
Definitions
expression
A valid sequence of operand(s) and operator(s) that reduces (or
evaluates) to a single value.
operator
A language-specific syntactical token (usually a symbol) that causes an
action to be taken on one or more operands.
operand
A value that receives the operator's action.
precedence
Determines the order in which the operators are allowed to manipulate
the operands.
associativity
Determines the order in which the operators of the same precedence
are allowed to manipulate the operands.
evaluation
The process of applying the operators to the operands and resulting in
a single value.
parentheses
Change the order of evaluation in an expression. You do what's in the
parentheses first.
An Expression Example with Evaluation
Let's look at an example: 2 + 3 * 4+ 5 is our expression but what does it
equal?
1. the symbols of + meaning addition and * meaning multiplication are
our operators
. the values 2, 3, 4 and 5 are our operands
. precedence says that multiplication is higher than addition
. thus, we evaluate the 3 * 4 to get 12
.now we have: 2+ 12+5
. the associativity rules say that addition goes left to right, thus we
evaluate the 2 +12 to get 14
7.now we have: 14+ 5
8. finally, we evaluate the 14 + 5 to get 19; which is the value of the
expression
AuKRWN
Parentheses would change the outcome. (2 + 3) * (4 + 5) evaluates to 45.
Parentheses would change the outcome. (2 + 3) * 4+ 5 evaluates to 25.
Precedence of Operators Chart
Each computer language has some rules that define precedence and
associativity. They often follow rules we may have already learned.
Multiplication and division come before addition and subtraction is a rule
we learned in grade school. This rule still works. The precedence rules vary
from one programming language to another. You should refer to the
reference sheet that summarizes the rules for the language that you are
using. It is often called a Precedence of Operators Chart. You should review
this chart as needed when evaluating expressions.
A valid expression consists of operand(s) and operator(s) that are put
together properly. Why the (s)? Some operators are:
1. Unary — that is only have one operand
2. Binary — that is have two operands, one on each side of the operator
3. Trinary — which has two operator symbols that separate three operands
Most operators are binary, that is they require two operands. Within C++
there is only one trinary operator, the conditional. All of the unary operators
are on the left side of the operand, except postfix increment and postfix
decrement. Some precedence charts indicate of which operators are unary
and trinary and thus all others are binary.
Assignment Operator
An explanation of the assignment operator with examples as used in the
C++ programming language.
Discussion
The assignment operator allows us to change the value of a modifiable data
object (for beginning programmers this typically means a variable). It is
associated with the concept of moving a value into the storage location
(again usually a variable). Within C++ programming language the symbol
used is the equal symbol. But bite your tongue, when you see the = symbol
you need to start thinking: assignment. The assignment operator has two
operands. The one to the left of the operator is usually an identifier name
for a variable. The one to the right of the operator is a value.
Example:
Simple Assignment
int age; // variable set up
then later in the program
age = 21;
The value 21 is moved to the memory location for the variable named: age.
Another way to say it: age is assigned the value 21.
Example:
Assignment with an Expression
int total_cousins; // variable set up
then later in the program
EOkalhcCOUSdhS = 44k 3 4 5 2
The item to the right of the assignment operator is an expression. The
expression will be evaluated and the answer is 14. The value 14 would
assigned to the variable named: total_cousins.
Example:
Assignment with Identifier Names in the Expression
int students_period_1 = 25; // variable set up
with initialization
int students_period_2
int total_students;
then later in the program
total_students = students_period_1 +
students_period_2;
iy
The expression to the right of the assignment operator contains some
identifier names. The program would fetch the values stored in those
variables; add them together and get a value of 44; then assign the 44 to the
total_students variable.
Definitions
assignment
An operator that changes the value of a modifiable data object.
Arithmetic Operators
An overview of the arithmetic operators within the C++ programming
language.
General Discussion
An operator performs an action on one or more operands. The common
arithmetic operators are:
Action C ++ operator symbol
Addition +
Subtraction 7
Multiplication =
Division /
Modulus (associated with integers) %
These arithmetic operators are binary that is they have two operands. The
operands may be either constants or variables.
age + 1
This expression consists of one operator (addition) which has two operands.
The first is represented by a variable named age and the second is a literal
constant. If age had a value of 14 then the expression would evaluate (or be
equal to) 15.
These operators work as you have learned them throughout your life with
the exception of division and modulus. We normally think of division as
resulting in an answer that might have a fractional part (a floating-point
data type). However, division when both operands are of the integer data
type act differently. Please refer to the supplemental materials on "Integer
Division and Modulus".
Data Type Conversions
Implicit and explicit type conversion with both promotion and demotion is
discussed with some examples.
Overview
Changing a data type of a value is referred to as "type conversion". There
are two ways to do this:
1. Implicit — the change is implied
2. Explicit — the change is explicitly done with the cast operator
The value being changed may be:
1. Promotion — going from a smaller domain to a larger domain
2. Demotion — going from a larger domain to a smaller domain
Implicit Type Conversion
Automatic conversion of a value from one data type to another by a
programming language, without the programmer specifically doing so, is
called implicit type conversion. It happens when ever a binary operator has
two operands of different data types. Depending on the operator, one of the
operands is going to be converted to the data type of the other. It could be
promoted or demoted depending on the operator.
Example:
Implicit Promotion
55 hw 5
In this example the integer value 55 is converted to a floating-point value
(most likely double) of 55.0. It was promoted.
Example:
Implicit Demotion
int money; // variable set up
then later in the program
money = 23.16;
In this example the variable money is an integer. We are trying to move a
floating-point value 23.16 into an integer storage location. This is demotion
and the floating-point value usually gets truncated to 23.
Promotion
Promotion is never a problem because the lower data type (smaller range of
allowable values) is sub set of the higher data type (larger range of
allowable values). Promotion often occurs with three of the standard data
types: character, integer and floating-point. The allowable values (or
domains) progress from one type to another. That is the character data type
values are a sub set of integer values and integer values are a sub set of
floating-point values; and within the floating-point values: float values are a
sub set of double. Even though character data represent the alphabetic
letters, numeral digits (0 to 9) and other symbols (a period, $, comma, etc.)
their bit pattern also represent integer values from 0 to 255. This
progression allows us to promote them up the chain from character to
integer to float to double.
Demotion
Demotion represents a potential problem with truncation or unpredictable
results often occurring. How do you fit an integer value of 456 into a
character value? How do you fit the floating-point value of 45656.453 into
an integer value? Most compilers give a warning if it detects demotion
happening. A compiler warning does not stop the compilation process. It
does warn the programmer to check to see if the demotion is reasonable.
If I calculate the number of cans of soup to buy based on the number of
people I am serving (say 8) and the servings per can (say 2.3), I would need
18.4 cans. I might want to demote the 18.4 into an integer. It would truncate
the 18.4 into 18 and because the value 18 is within the domain of an integer
data type, it should demote with the truncation side effect.
If I tried demoting a double that contained the number of stars in the Milky
Way galaxy into an integer, I might have a get an unpredictable result
(assuming the number of stars is larger than allowable values within the
integer domain).
Explicit Type Conversion
Most languages have a method for the programmer to change or cast a
value from one data type to another; called explicit type conversion.
Within C++ the cast operator is a unary operator; it only has one operand
and the operand is to the right of the operator. The operator is a set of
parentheses surrounding the new data type.
Example:
Explicit Demotion with Truncation
(ine eae
This expression would evaluate to: 4.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the soruce code file(s) in
conjunction with other learning materials.
Definitions
implicit
A value that has its data type changed automatically.
explicit
Changing a value's data type with the cast operator.
promotion
Going from a smaller domain to a larger domain.
demotion
Going from a larger domain to a smaller domain.
truncation
The fractional part of a floating-point data type that is dropped when
converted to an integer.
Practice 3: Data & Operators
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Understand basic data types and how operators manipulate data.
3. Given pseudocode and test data documents, write the C++ code for a
program
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. A data type defines a set of values and the set of operations that
can be applied on those values.
2. Reserved or key words can be used as identifier names.
3. The concept of precedence says that some operators (like
multiplication and division) are to be executed before other
operators (like addition and subtraction).
4. An operator that needs two operands, will promote one of the
operands as needed to make both operands be of the same data
type.
5. Parentheses change the precedence of operators.
Solution:
Answers:
1. true
2. false
3. true
4. true
5. false — Parentheses change the order of evaluation in an
expression.
Miscellaneous Items
Link to: Manipulation of Data Part 1
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 03 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_03 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Solution Lab 03 Pseudocode.txt
Download from Connexions: Solution Lab 03 Test Data.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Navigate to your sub-folder: Chapter_03 and open and study the two
files.
e We have learned that a fundamental concept of interaction with
computers is to divide the problem/task into three parts — input,
processing and output. This problem is simple and we will use the
IPO (input — processing — output) approach again. However this time
we are going to think about it backwards.
e¢ What output do I want displayed?
¢ Number of gallons of paint
¢ Total cost of the paint
e Thus, what calculations do I need to make?
¢ Total cost of the paint is the Number of gallons needed times price per
gallon
e Number of gallons needed is the Total area to be covered (let’s use
square feet) divided by the coverage per gallon of paint (Note: you
must round up to the next full gallon of paint.)
e Total area to be covered is the Length times height times 2 added to the
width times height times 2
e Which leads us to, what data do I need as input?
e Price of a gallon of paint
e Number of square feet that a gallon will cover
e Length of the house
e Width of the house
¢ Height of the house
e You can see that by working the logic backwards, we can start to
completely see what the program must do. We need to enter some data
(input), do some calculations (process) and display the results (output).
¢ Copy into your sub-folder: Chapter_03 one of the source code listings
that we have used (we suggest the Lab 01 source code) and rename the
copy to: Lab_03.cpp
¢ Modify the code to follow the Solution_Lab_03_Pseudocode.txt file.
e I am just going to give you the line of code for rounding up to the next
whole gallon of paint (See the “Data Type Conversions” module
within Chapter 3 of the Connexions materials. Do you understand why
it works?).
¢ total_gal_paint = total_area / coverage_gal_paint + 0.9999;
e Build (compile and run) your program. You have successfully written
this program when it runs with your test data and gives the predicted
results.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 03a — Instructions
Write the C++ code to do the following pseudocode example.
Example:
pseudocode
Prompt the user for his monthly income.
Get the users monthly income.
Multiply the monthly income by 12.
Display the annual income.
Pause the program so the user can see the answer.
(HINT: You tay Calla TUNnCEION:, )
Integer Data Type
An introduction to the integer data type.
General Discussion
The integer data type has two meanings:
e The integer data type with its various modifiers that create different
domains
e The integer family which also includes the Boolean and character data
types
The integer data type basically represents whole numbers (no fractional
parts). The integer values jump from one value to another. There is nothing
between 6 and 7. It could be asked why not make all your numbers floating
point which allow for fractional parts. The reason is twofold. First, some
things in the real world are not fractional. A dog, even with only 3 legs, is
still one (1) dog not % of a dog. Second, integer data type is often used to
control program flow by counting, thus the need for a data type that jumps
from one value to another.
The integer data type has the same attributes and acts or behaves similarly
in all programming languages. The most often used integer data type in
C++ is the simple integer.
C++ Reserved Word int
Represent Whole numbers (no fractional parts)
Size Usually 4 bytes
Normal Signage Signed (negative and positive values)
Domain (Values Allowed) -2,147,483,648 to 2, 147,483,647
C++ syntax rule Do not start with a 0 (zero)
C++ syntax rule No decimal point
Within C++ there are various reserved words that can be used to modify the
size or signage of an integer. They include: long, short, signed and
unsigned. Signed is rarely used because integers are signed by default — you
must specify unsigned if you want integers that are only positive. Possible
combinations are:
C++ Reserved Word Combination Signage
short int signed
unsigned short int unsigned
int signed
unsigned int unsigned
long int singed
unsigned long int unsigned
The domain of each of the above data type options varies with the complier
being used and the computer. The domains vary because the byte size
allocated to the data varies with the compiler and computer. This effect is
known as being machine dependent. Additionally, there have been some
size changes with upgrades to the language. In "C" the int data type was
allocated 2 bytes of memory storage on an Intel compatible central
processing unit (cpu) machine. In "C++" an int is allocated 4 bytes.
These variations of the integer data type are an annoyance in C++ fora
beginning programmer. For a beginning programmer it is more important to
understand the general attributes of the integer data type that apply to most
programming languages.
Definitions
machine dependent
An attribute of a programming language that changes depending on the
computer's CPU.
Floating-Point Data Type
An explanation of the floating-point data type to include: float, double and
long double.
General Discussion
The floating-point data type is a family of data types that act alike and differ
only in the size of their domains (the allowable values). The floating-point
family of data types represent number values with fractional parts. They are
technically stored as two integer values: a mantissa and an exponent. The
floating-point family has the same attributes and acts or behaves similarly
in all programming languages. They can always store negative or positive
values thus they always are signed; unlike the integer data type that could
be unsigned. The domain for floating-point data types varies because they
could represent very large numbers or very small numbers. Rather than talk
about the actual values, we mention the precision. The more bytes of
storage the larger the mantissa and exponent, thus more precision.
The most often used floating-point family data type used in C++ is the
double. By default, most compilers convert floating-point constants into the
double data type for use in calculations. The double data type will store just
about any number most beginning programmers will ever encounter.
C++ Reserved
Word double
Represent Numbers with fractional parts
Size Usually 8 bytes
Storage two parts (always treated together)a mantissa
and an exponent
Normal Signage Signed (negative and positive values)
Domain (Values
= - +
Allowed) +1.7E-308 to +1.7E308
the presence of a decimal point means it’s
C++ syntax rule floating-point data
Within C++ there are various reserved words that can be used to establish
the size in bytes of a floating-point data item. More bytes mean more
precision:
C++ Reserved Word Size
float 4 bytes
double 8 bytes
long double 10 to 12 bytes (varies by machine)
The domain of each of the above data type options varies with the complier
being used and the computer. The domains vary because the byte size
allocated to the data varies with the compiler and computer. This effect is
known as being machine dependent.
These variations of the floating-point family of data types are an annoyance
in C++ for a beginning programmer. For a beginning programmer it is more
important to understand the general attributes of the floating-point family
that apply to most programming languages.
Definitions
double
The most often used floating-point family data type used in C++.
precision
The effect on the domain of floating-point values given a larger or
smaller storage area in bytes.
mantissa exponent
The two integer parts of a floating-point value.
String Data Type
An introduction to the string concept and it's use as a string constant.
General Discussion
Technically, there is no string data type in the C++ programming language.
However, the concept of a string data type makes it easy to handle strings of
character data. A single character has some limitations. Many data items are
not integers or floating-point values. The message Hi Mom! is a good
example of a string. Thus, the need to handle a series of characters as a
single piece of data (in English correctly called a datum).
In the "C" programming language all string were handled as an array of
characters that end in an ASCII null character (the value 0 or the first
character in the ASCII character code set). Associated with object oriented
programming the string class has been added to C++ as a standard part of
the programming language. This changed with the implementation with
strings being stored as a length controlled item with a maximum length of
255 characters. Included in the C++ string class is the reserved word of
string as if it were a data type. Some basics about strings include:
C++ Reserved Word string
Series of characters (technically an
Represent
array)
Size Varies in length
Normal Signage N/A
Domain (Values
Allowed) Extended ASCII Character Code Set
C++ syntax rule Double quote marks for constants
For now, we will address only the use of strings as constants. Most modern
compliers that are part of an Integrated Development Environment (IDE)
will color the source code to help the programmer see different features
more readily. Beginning programmers will use string constants to send
messages to the monitor. A typical line of C++ code:
cout << "Hi Mom! ”;
would have the "Hi Mom" colored (usually red) to emphasize that the item
is a string.
Definitions
string
A series or array of characters as a single piece of data.
Arithmetic Assignment Operators
A table showing the equivalent meaning for the arithmetic assignment
operators.
Overview of Arithmetic Assignment
The five arithmetic assignment operators are a form of short hand. Various
textbooks call them "compound assignment operators" or "combined
assignment operators". Their usage can be explaned in terms of the
assignment operator and the arithmetic operators. In the table we will use
the variable age and you can assume that it is of integer data type.
Arithmetic assignment examples: Equivalent code:
age += 14; age = age + 14;
age -= 14; age = age - 14;
age *= 14; age = age * 14;
age /= 14; age = age / 14;
age %= 14; age = age % 14;
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the soruce code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo Arithmetic Assignment.cpp
Lvalue and Rvalue
Concepts and examples of Lvalue and Rvalue within the C++ programming
language.
Discussion
They refer to on the left and right side of the assignment operator. The
Lvalue (pronounced: L value) concept refers to the requirement that the
operand on the left side of the assignment operator is modifiable, usually a
variable. Rvalue concept pulls or fetches the value of the expression or
operand on the right side of the assignment operator. Some examples:
Example:
int age; // variable set up
then later in the program
age = 39;
The value 39 is pulled or fetched (Rvalue) and stored into the variable
named age (Lvalue); destroying the value previously stored in that variable.
Example:
int age; // variable set up
int voting_age = 18; // variable set up with
bj qjal (a alreld babrars ie 30/0)
then later in the program
age = voting_age;
If the expression has a variable or named constant on the right side of the
assignment operator, it would pull or fetch the value stored in the variable
or constant. The value 18 is pulled or fetched from the variable named
voting age and stored into the variable named age.
Example:
age < 17;
If the expression is a test expression or Boolean expression, the concept is
still an Rvalue one. The value in the identifier named age is pulled or
fetched and used in the relational comparison of less than.
Example:
const int JACK_BENNYS_AGE = 39; // constant set
up
then later in the program
JACK_BENNYS_AGE = 65;
This is illegal because the identifier JACK_BENNYS_AGE does not have
Lvalue properties. It is not a modifiable data object, because it is a constant.
Some uses of the Lvalue and Rvalue can be confusing.
Example:
int oldest = 55; // variable set up with
pl pjalimalrs) Malvern ea lio q|
then later in the program
age = oldest++;
Postfix increment says to use my existing value then when you are done
with the other operators; increment me. Thus, the first use of the oldest
variable is an Rvalue context where the existing value of 55 is pulled or
fetched and then assigned to the variable age; an Lvalue context. The
second use of the oldest variable is an Lvalue context where in the value of
oldest is incremented from 55 to 56.
Definitions
Lvalue
The requirement that the operand on the left side of the assignment
operator is modifiable, usually a variable.
Rvalue
Pulls or fetches the value stored in a variable or constant.
Integer Division and Modulus
An explanation of integer division with an example of how this was learned
in grade school as your first method of understanding division before
fractions. The modulus operator is explained.
Overview of Integer Division and Modulus
By the time we reach adulthood, we normally think of division as resulting
in an answer that might have a fractional part (a floating-point data type).
This type of division is known as floating-point division. However,
division when both operands are of the integer data type acts differently on
most computers and is called: integer division. Within the C++
programming language the following expression does not give the answer
of 2.75 or 2%.
Example:
pal, cg!
Because both operands are of the integer data type the evaluation of the
expression (or answer) would be 2 with no fractional part (it gets thrown
away). Again, this type of division is call integer division and it is what
you learned in grade school the first time you learned about division.
integer division
Division with no fractional parts.
Integer division as
learned in grade
school.
In the real world of data manipulation there are some things that are always
handled in whole units or numbers (integer data type). Fractions just
don’t exist. To illustrate our example: I have 11 dollar coins to distribute
equally to my 4 children. How many do they each get? Answer is 2 with
me still having 3 left over (or with 3 still remaining in my hand). The
answer is not 2 %4 each or 2.75 for each child. The dollar coins are not
divisible into fractional pieces. Don’t try thinking out of the box and
pretend you’re a pirate. Using an axe and chopping the 3 remaining coins
into pieces of eight. Then, giving each child 2 coins and 6 pieces of eight or
2 6/8 or 2 % or 2.75. If you do think this way, I will change my example to
cans of tomato soup. I dare you to try and chop up three cans of soup and
give each kid % of a can. Better yet, living things like puppy dogs. After
you divide them up with an axe, most children will not want the % of a dog.
What is modulus? It's the other part of the answer for integer division. It’s
the remainder. Remember in grade school you would say, "Eleven divided
by four is two remainder three." In C++ programming language the symbol
for the modulus operator is the percent sign (%).
Example:
11 % 4
Thus, the answer or value of this expression is 3 or the remainder part of
integer division.
modulus
The remainder part of integer division.
Many compilers require that you have integer operands on both sides of the
modulus operator or you will get a compiler error. In other words, it does
not make sense to use the modulus operator with floating-point operands.
Don’t let the following items confuse you.
Example:
6 / 24 which is different from 6 % 24
How many times can you divide 24 into 6? Six divied by 24 is zero. This is
different from: What is the remainder of 6 divided by 24? Six, the
remainder part given by modulus.
Exercise:
Problem:
Evaluate the following division expressions:
1.14/4
2.39 13
oJ 420
Solution:
Answers:
ra
.0
. 3.5 because one of the operands is a floating-point value, it is not
integer division
WN FR
Exercise:
Problem:
Evaluate the following modulus expressions:
1.14% 4
2.3 Jol
3.1 Von
Solution:
Answers:
1,2
225
3. "error" because most compilers require both operands to be of the
integer data type
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file. Following the methods of
your compiler/IDE, compile and run the program(s). Study the soruce code
file(s) in conjunction with other learning materials.
Download from Connexions: Demo _ Integer Division and Modulus.cpp
Practice 4: Often Used Data Types
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Design a program, to include: understanding the problem, completing
Internet research as appropriate, create a pseudocode document and
create a test data document.
3. Write the C++ code for a program using appropriate planning
documentation that you or another has designed.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Integer data types are stored with a mantissa and an exponent.
2. Strings are identified by single quote marks.
3. An operand is a value that receives the operator’s action.
4. Arithmetic assignment is a shorter way to write some expressions.
5. Integer division is rarely used in computer programming.
Solution:
Answers:
1. false
2. false
3. true
4. true
5. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 04 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_04 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e The Problem/Task — I have a friend who is visiting from Europe and he
does not understand Fahrenheit temperatures. We need to write a
program that allows him to enter the temperature in Fahrenheit (as
announced on TV or radio) and convert it to Celsius. Clue 1:
Fahrenheit water freezes at 32 degrees and boils at 212 degrees.
Celsius water freezes a zero (0) degrees and boils at 100 degrees.
Google the internet (how to convert Fahrenheit to Celsius) if you need
more help. Clue 2: You can also use Internet sites to do a conversion
and thus create your test data.
e You only need two variables in this program: Fahrenheit and Celsius
both of which should be the integer data type. When you convert the
Fahrenheit to Celsius you will need to use a floating-point expression
doing floating-point calculations for precision. Additionally we want
to round up or down the Celsius answer by adding 0.5 to the
calculation expression.
e Within your sub-folder: Chapter_04 you will need to create three files:
Lab_04_Pseudocode.txt and Lab_04_Test_Data.txt and Lab_04.cpp
NOTE: It will be easier to copy some previous files from another
assignment and use those copies by renaming them and modifying
them as appropriate. The professor is expecting the items you create to
have a similar format to those we have been using in the course.
e Create your pseudocode, test data and source code files.
¢ Build (compile and run) your program. You have successfully written
this program when it runs with your test data and gives the predicted
results.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 04a — Instructions
Decide on the data type and identifier names for the following:
Problem: A men's clothing store that caters to the very rich wants to create a
data base for its customers that records clothing measurements. They need
to record information for shoes, socks, pants, dress shirts and casual shirts.
HINT: You may need more than 5 data items.
Integrated Development Environment
An explanation of how an IDE processes a source code file into a program
that runs on the computer. Categories of errors are discussed and
demonstrated with C++ source code files that can be downloaded for
practice.
IDE Overview
High-level language programs are usually written (coded) as ASCII text
into a source code file. A unique file extension (Examples: .asm .cob .for
.pas .c .cpp) is used to identify it as a source code file. As you can guess for
our examples — Assembly, COBOL, FORTRAN, Pascal, "C" and "C++"
however, they are just ASCII text files (other text files usually use the
extension of .txt). The source code produced by the programmer must be
converted to an executable machine code file specifically for the computer’s
CPU (usually an Intel or Intel compatible CPU within today’s world of
micro computers). There are several steps in getting a program from its
source code stage to running the program on your computer. Historically,
we had to use several software programs (a text editor, a compiler, a linker
and operating system commands) to make the conversion and run our
program. However, today all those software programs with their associated
tasks have been integrated into one program usually called a compiler.
However, this one compiler program is really many software items that
create an environment used by programmers to develop software. Thus the
name: Integrated Development Environment or IDE.
The following figure shows the progression of activity in an IDE as a
programmer enters the source code and then directs the IDE to compile and
run the program.
Files Created IDE Software Used
Monitor showing source code
Library headers
pgm_name.obj
Library objects
7
Outputs
Loader
~ Monitor running the program
Integrated Development Environment or IDE
pgm_name.exe
Upon starting the IDE software the programmer usually indicates he wants
to open a file for editing as source code. As they make changes they might
either do a "save as" or "save". When they have finished entering the source
code, they usually direct the IDE to "compile & run" the program. The IDE
does the following steps:
1. If there are any unsaved changes to the source code file it has the test
editor save the changes.
2. The compiler opens the source code file and does its first step which
is executing the pre-processor compiler directives and other steps
needed to get the file ready for the second step. The #include will
insert header files into the code at this point. If it encounters an error, it
stops the process and returns the user to the source code file within the
text editor with an error message. If no problems encountered it saves
the source code to a temporary file called a translation unit.
3. The compiler opens the translation unit file and does its second step
which is converting the programming language code to machine
instructions for the CPU, a data area and a list of items to be resolved
by the linker. Any problems encounted (usually a syntax or violation
of the programming language rules) stops the process and returns the
user to the source code file within the text editor with an error
message. If no problems encountered it saves the machine instructions,
data area and linker resolution list as an object file.
4. The linker opens the program object file and links it with the library
object files as needed. Unless all linker items are resolved, the process
stops and returns the user to the source code file within the text editor
with an error message. If no problems encountered it saves the linked
objects as an executable file.
5. The IDE directs the operating system’s program called the loader to
load the executable file into the computer's memory and have the
Central Processing Unit (CPU) start processing the instructions. As the
user interacts with the program, entering his test data, he might
discover that the outputs are not correct. These types of errors are
called logic errors and would require him to return to the source code
to change the algorithm.
Resolving Errors
Despite our best efforts at becoming perfect programmers, we will create
errors. Solving these errors is known as debugging your program. The three
types of errors in the order that they occur are:
1. Compiler
2. Linker
3. Logic
There are two types of compiler errors; pre-processor (1st step) and
conversion (2nd step). A review of Figure 1 above shows the four arrows
returning to the source code so that the programmer can correct the mistake.
During the conversion (2nd step) the complier might give a warning
message which in some cases may not be a problem to worry about. For
example: Data type demotion may be exactly what you want your program
to do, but most compilers give a warning message. Warnings don't stop the
compiling process but as their name implies, they should be reviewed.
The next three figures show IDE monitor interaction for the Bloodshed
Dev-C++ 5 compiler/IDE.
eid Dev-C++ 4.9.9.2 sre x=
File Edit Search View Project Execute Debug Tools CVS Window Help
\SGlOE8ea|S)\s-|5E85)| 8) aa\9|
[33 BEY |? @)) Drew dijinset i Toaale [ll] Goto
i aI =|
Projet | Classes | Debug] Compiler Test_wth Enor.cpp |
// debug and run a program on your c
// Complier: Multi complier comp.
#include <iostream>
using namespace std;
// Function Prototypes
void pause (void);
// Variables
int agei;
int age2;
double answer;
/ Input
cout << "\nEnter the age of the first person --->: ";
cin >> agel;
cin >> age2;
ip ie
Ga Compiler | fy Resources | dh Compile Log | w Debug| [KA Find Results |] Close |
Line | File Message
C:\Users\ken.busbee\Documents\03... In function ‘int main{}':
40 C:\Users\ken.busbee\Documents\03... “cxout' undeclared [first use this function)
(Each undeclared identifier is reported only once for each function it appears in.)
[aoa |
[Insert file
Compiler Error (the red line is where the complier stopped)
la) Dev-C++ 4.9.9.2 (oan ceP fa
File Edit Search View Project Execute Debug Tools CVS Window Help
(Gees Sie?) G88) 8) aa 8)
OBZ | PO | new inset Toacle [Hl] Goto
I || |
Project | Classes| Debug] Compiler_Test_with Eor.cpp |
int agel; A
Bo Compile | ij Resources
int age2;
double answer;
[[dttbeeeteaeneaeenetebecetaaaesasenesaeeeeeseseeeaeeees
int main (void)
{
// Input
cout << "\nEnter the age of the first person --->: ";
cin >> agel;
dput << "\nEnter the age of the second person -->: ";
cin >> age2;
m
// Process
answer = (agel + age2) / 2.0;
// Output
cout << "\nThe average of their ages is --------: ot. "2
cout << answer;
pause ();
return 0;
by
[[attaeneeecatesaaesaetesseesaeeesessssepsaesesesesaeees
Hh Compile Log| ¢ Debug | [A Find Results | #3] Close |
Line | File Message
[Linker error] undefined reference to ‘pause(]'
Id retumed 1 exit status
(404 | [Insert 74 Lines in fle
Linker Error (no red line with an error message describing linking
problem)
eh Dev-c 4992 ole) s]
SqE Eas |s)\* BEB A
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I =| g
Project | Classes | jg C:\Users\ken.busbee\Documents\03 Connexions\2 Modular Programming\25 Integrated Development Envir... = |C| x;
int main(void)
{
cout << "\nEnter the age of the first person --->: ":
cin >> agel;
cout << "\nEnter the age of the second person -->: ";
cin >> age2;
Output
BS Compiler | iy Resources | dl Compile Log | ~7 Debug | [E\ Find Resuts |
40:4 Insert 74 Lines in file
< WOO 1.00PM
Logic Error (from the output within the "Black Box" area)
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the soruce code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo Pre Processor Compiler Errors.cpp
Download from Connexions: Demo Compiler Conversion Errors.cpp
Download from Connexions: Demo Linker Errors.cpp
Download from Connexions: Demo Logic Errors.cpp
Definitions
text editor
A software program for creating and editing ASCII text files.
compiler
Converts source code to object code.
pre-processor
The first step the complier does in converting source code to object
code.
linker
Connects or links object files into an executable file.
loader
Part of the operating system that loads executable files into memory
and direct the CPU to start running the program.
debugging
The process of removing errors from a program. 1) compiler 2) linker
3) logic
warning
A compiler alert that there might be a problem.
Standard Input and Output
An explanation of standard input and output as used in the computer
industry followed by examples of cin and cout as used within a C++
program.
General Discussion
Every task we have the computer do happens inside the central processing
unit (CPU) and the associated memory. Once our program is loaded into
memory and the operating system directs the CPU to start executing our
programming statements the computer looks like this:
Central Processing Unit Input/Output Devices
Punched Card
Printed Reports
C) Tape Storage
Disk Drive Storage
sive ne
=
Keyboard Monitor
CPU — Memory — Input/Output Devices
Our program now located in the memory has basically two areas:
e Machine instructions — our instructions for what we want done
e Data storage — our variables that we using in our program
Often our program contains instructions to interact with the input/output
devices. We need to move data into (read) and/or out of (write) the memory
data area. A device is a piece of equipment that is electronically connected
to the memory so that data can be transferred between the memory and the
device. Historically this was done with punched cards and printouts. Tape
drives were used for electronic storage. With time we migrated to using disk
drives for storage with keyboards and monitors (with monitor output called
soft copy) replacing punch cards and printouts (called hard copy).
Most computer operating systems and by extension programming languages
have identified the keyboard as the standard input device and the monitor
as the standard output device. Often the keyboard and monitor are treated
as the default device when no other specific device is indicated.
Standard I/O within C++
The developers of the C++ programming language decided to provide some
of the more technical code needed to interact with the operating system and
the I/O devices. In the following example the include directive inserts a file
that contains code from the Input-Output Stream library. This file
contains necessary code to use cout and cin for sending data to the monitor
or getting data from the keyboard.
#include <iostream>
You should think of cout and cin as being locations that you can send to or
receive data from; similar in concept to any other variable storage location
within the data area of our program. The C++ programming language has
two operators to use in conjunction with I/O devices.
Used
Action C ++ operator symbol aa
insertion operator << (a pair of less than fant
(write) symbols)
extraction operator >> (a pair of greater than cin
(read) symbols)
Consider the following code:
Example:
Insertion and Extraction
int age1; // variable set up
then later on in our program
cout << "\nEnter the age of the first person --->:
T
Cin >> age;
Using the cout the programmer displays (or inserts) a prompting message
on the monitor for the user to see. Using the cin the user types an integer
value and hits the enter key and the computer extracts the value from the
keyboard and stores it into the variable named age1. Within the computer
all data are stored as numbers and thus part of the technical code provided
by the developers of the C++ programming language that is within the
Input-Output Stream library converts data from numbers to those symbols
we are used to seeing as humans and vice versa. Example: If the user
entered the numeral digits 57 and hit the enter key — the extraction operator
would convert the 57 into a binary number and move the binary number
into the integer storage place named age1.
The cout which uses the standard output device does not format the output
into a Graphical User Interface (GUI) where you have a mouse to use. A
modern operating system using GUI normally opens a black screen output
box that would be similar to how the monitor was used when first
developed in the 1960's. That is the default of how cout is normally
implemented by most compilers.
The output message has a unique item worth mentioning. At the very front
of the message is a backslash followed by the letter n. They do not get
printed on the monitor. It is a special code (called a printer escape code)
telling the printer to go to a new line. Printer! I thought we were using a
monitor? We are but the code is a left over from the early days of printer
output. The backslash tells the printer or monitor that the next letter is a
command. The letter n is used for telling the printer or monitor to go to the
front of a new line.
Definitions
device
A piece of equipment that is electronically connected to the memory so
that data can be transferred between the memory and the device.
standard input
The keyboard.
standard output
The monitor.
insertion
Aka writing or sending data to an output device.
extraction
Aka reading or getting data from an input device.
escape code
A code directing an output device to do something.
Compiler Directives
A general explanation of pre-processor directives and how they are
evaluated by the compiler. Discussed are include and define.
General Discussion
A compiler directive is an instruction to the compiler to complete a task
before formally starting to compile the program, thus they are sometimes
called pre-processor directives. Among other items, during the pre-
processor step the compiler is looking for compiler directives and processes
them as they are encountered. After completing the tasks as directed, the
compiler proceeds to its second step where it checks for syntax errors
(violations of the rules of the language) and converts the source code into
an object code that contains machine language instructions, a data area, and
a list of items to be resolved when he object file is linked to other object
files.
Within C++ the pound symbol or # as the first character of a line indicates
that the next word is a directive (or command word) to be evaluated. The
two most common compiler directives are:
1. include — with the item following include being the name of a file that
is to be inserted at that place in the file. The files are often called
"Header Files" because the include directive is normally inserted
toward the top of the file (at the head) as one of the first items.
2. define — with the item followed by an identifier name and a value.
This identifier name and value is stored by the compiler and when it
encounters the identifier name in the program it substitutes the value
for the identifier name.
In the following example the include directive is inserting a file that
contains code from the Input-Output Stream library. This file contains
necessary code to use cout and cin for sending data to the monitor or getting
data from the keyboard.
#include <iostream>
In the next example the define directive is being used to handle a constant
(called a defined constant).
Example:
Subtituting PI
#define PI 3.14159
....Later on in the program when it encounters PI
....1it will replace or substitute PI with the
value 3.14159
....FOr example:
area_circle = radius * radius * PI;
would become:
area_carcle = radius *~ radius * 3.14159:
Of note, compiler directives in C++ do not have a semi-colon after them.
Within C++ programming instructions or statements end with a semi-colon,
but not compiler directives.
Definitions
compiler directive
An instruction to the compiler to complete a task before formally
starting to compile the program.
include
A compiler directive to insert the contents of a file into the program.
Practice 5: Integrated Development Environment
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Be able to list the categories and give examples of errors encountered
when using an Integrated Development Environment (IDE).
3. Write the C++ code for a program using appropriate planning
documentation that you or another has designed.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. IDE means Integer Division Expression.
2. Most modern compilers are really an IDE type of software, not
just a compiler.
3. cin and cout are used for the standard input and output in C++.
4. Programming errors are extremely easy to understand and fix.
5. All C++ programs will have at least one include type of compiler
directive.
Solution:
Answers:
1. false
2. true
3. true
4. false
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 05 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_05 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Solution Lab 02 Pseudocode.txt
Download from Connexions: Solution Lab 02 Test Data.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
¢ Copy into your sub-folder: Chapter_05 one of the source code listings
that we have used. We suggest the Lab 01 source code and rename the
copy: Lab_05.cpp
¢ Modify the code to follow the Solution_Lab_02_Pseudocode.txt file.
e Build (compile and run) your program. You have successfully written
this program if when it runs and you use the test data [use the test data
as supplied as the solution for Lab 02] it gives the predicted results.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 05a — Instructions
List and describe what might cause the four (4) types of errors encountered
in a program using an Integrated Development Environment software
product.
Problem 05b — Instructions
Identify four (4) problems with this code listing (HINT: The four (4) types
of errors encountered in a program using an Integrated Development
Environment software product).
Example:
C++ Source Code Listing
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KER ak
// Filename: Compiler_Test.cpp
// Purpose: Average the ages of two people
// Author: Ken Busbee; © Kenneth Leroy Busbee
// Date: Jan 5, 2009
// Comment: Main idea is to be able to
77 debug and run a program on your
compiler.
a
KKEKKKK
// Headers and Other Technical Items
#include <iostrern>
uSing namespace std;
// Function Prototypes
void pause(void);
// Nariables
abi gis agel;
int age2,
double answear;
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// main
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int main(void)
iL
7 UU
cout << "\nEnter the age of the first person ---
Pa ee
Cin >> age;
cout << "\nEnter the age of the second person --
> aie
cin >> age2;
// Process
answer = (agel + age2) / 3.0;
7/7 SOUEDUE
cout << "\nThe average of their ages is --------
>: Ws
, y
cout << answer;
pause();
return 0;
i
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Kee K KK
// End of Program
PE AE eis AES EB RGSS aS OS TDC s SUSE ES GIES LIE EEG Rah CS ale a tad Ce CA SG OS ERE IES ep
RRR KKK
Pseudocode Examples for Functions
Suggested pseudocode conventions for functions along with some
examples.
Concept
No standard for pseudocode syntax exists. However, there are some
commonly followed conventions to help make pseudocode written by one
programmer easily understood by another programmer. The following
describes a method for using pseudocode for functions that would be
understood by programmers. Five concepts are:
e Use a beginning phrase word to start the function
e Use a communication phrase word to identify the items being passed
into the function
e Use indentation to show the action part of the function
e Use a communication phrase word to identify the items being passed
out of the function
e Use an ending phrase word to end the function
¢ Use a calling phrase word to direct your program to use a fucntion
The following is a suggested outline of function phrase words:
Starting Phrase Ending Phrase
Item/Purpose Word Word
Beginning Function N/A
Communication In Pass In: none
Action N/A N/A
Communication Pass Out: none
Out
Ending N/A Endfunction
Calling a Function Call: none
Examples
Here are some examples showing functions defined in pseudocode using
our conventions as described above.
Example:
pseudocode: Function with no parameter passing
Function clear monitor
Pass) In: nOrning
Direct the operating system to clear the monitor
Pass Out: nothing
Endfunction
Example:
pseudocode: Function with parameter passing
Function delay program so you can see the monitor
Pass In: integer representing tenths of a second
Using the operating system delay the program
Pass Out: nothing
Endfunction
Example:
pseudocode: Function main calling the clear monitor function
Function main
Pass In: nothing
Doing some lines of code
Call: clear monitor
Doing some lines of code
Pass Out: value zero to the operating system
Endfunction
Definitions
phrase word
Words used to make pseudocode logic clear to any reader.
Hierarchy or Structure Chart
An explanation of a hierarchy or structure chart with an example.
Overview
The hierarchy chart (also known as a structure chart) shows the
relationship of various units. Its name comes from its general use in
showing the organization (or structure) of a business. The President at the
top, then vice presidents on the next level, etc. Within the context of a
computer program it shows the relationship between modules (or
functions). Detail logic of the program is not presented. It does represent
the organization of the functions used within the program showing which
functions are calling on a subordinate function. Those above are calling
those on the next level down.
Hierarchy charts are created by the programmer to help document a
program. They convey the big picture of the modules (or functions) used in
a program.
main
process show
get data data results
pause
Hierarchy or Structure chart for a program that has five functions.
Definitions
hierarchy chart
Convey the relationship or big picture of the various functions in a
program.
structure chart
Another name for a hierarchy chart.
Program Control Functions
A general explanation of how functions are used to modularize a program.
Prerequisite Material
Critical to this module is the review of several Connexions modules:
1. m_18861 — Titled: Modularization and C++ Program Layout
2.m_19136 — Titled: Pseudocode Examples for Functions
3. m_18682 — Titled: Hierarchy or Structure Chart
You should review these materials before proceeding. If you are viewing
this module on-line, links to these items are in the "Links" box to your right.
Concept of Modularization
The concept is everywhere present in the real world about us. Simply put it
is to take a large complicated problem and to divide it into smaller
manageable pieces. The hierarchy chart of any large organization
(government unit, company, university, hospital, etc.) will show levels of
people with job titles that indicate a different area of responsibility. Each
person is a small piece of the overall workings of the organization. Each
person can concentrate on their unique talent or task to make sure it works
properly. Collectively they accomplish the goals of the organization.
Additionally, the concept has been around for a long time. A village of 300
years ago had farmers, tailors, butchers, blacksmiths, etc. Manufacturing is
a prime example of not just work being modularized but the product itself is
viewed in terms of modules or systems (Example of a automobile: engine,
steering, brakes, etc.).
The world of computers, both hardware (equipment) and software
(computer programs), also uses this modular concept. Thus, the concept
migrates to a single computer program; allowing us to modularize the
program into manageable tasks called functions.
Program Control Functions
Program Control functions normally do not communicate information to
each other but use a common area for variable storage. The rules for how
data is communicated in and out of a function vary greatly by programming
language, but the concept is the same. The data items passed (or
communicated) are called parameters. Thus the wording: parameter
passing. However, with program control functions we use the data
communication option of no communication in — with no communication
out. Our data variables and constants are placed in a common area available
to all functions (called global scope).
The identifier names for program control functions usually imply a task to
be accomplished, such as get-data, process-data or show-results. As you
learn to write more complicated programs the number of lines of code will
increase. Prudence dictates that it would be beneficial to divide the program
into functions that perform unique tasks. The larger the program the more
need for modularization or creating of program control functions.
Depending on the programming language, there is a formal way to:
1. define a function (it’s definition or the code it will execute))
2. call a function
3. declare a function (a prototype is a declaration to a complier)
One of the easier ways to understand program control function is to view an
example. Even if you don’t know the C++ programming language, you can
study the materials to help understand the modularization process.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on some of the links and
select "Save Target As" in order to download some of the files. Following
the methods of your compiler/IDE, compile and run the program(s). Study
the source code file(s) in conjunction with other learning materials.
Download from Connexions:
Demo Program Control Functions before Compiler Test.cpp
Download from Connexions:
Demo_ Program Control Functions Pseudocode.txt
Download from Connexions:
Demo Program Control Functions Hierarchy Chart.jpg
Download from Connexions: Demo Program Control Functions.cpp
Study the Materials Collectively to Understand Modularization
The four items represent a progression from no modularization to
modularization:
1. Program code before it is modularized
2. Modularized pseudocode and a hierarchy chart for the program
3. Program code that has been modularized
The simplicity of the program should not be considered during this review.
It is obvious that the program does not need modularization. The example is
to show or demonstrate how to modularize a program for program control.
Definitions
common area
An area of the program where variables and constants are defined so
that they are available to all functions.
Void Data Type
An explanation of the void data type.
General Discussion
The void data type has no values and no operations. It's a data type that
represents the lack of a data type.
C++ Reserved Word void
Represent Nothing
Size N/A or None
Normal Signage N/A
Domain (Values Allowed) None
This data type was added in the transition from "C" to "C++". In "C" by
default a function returned an integer data type. Some functions don't return
a value of any kind. Thus, the need to have a data type that indicates
nothing is being returned. The void data type is mainly used in the
definition and prototyping of functions to indicate that either nothing is
being passed in and/or nothing is being passed out.
Definitions
void data type
A data type that has no values or operators and is used to represent
nothing.
Documentation and Making Source Code Readable
A source code listing and discussion of several items that make source code
easier to read and maintain.
General Discussion
We are going to consider a simple program that might be used for testing a
compiler to make sure that it is installed correctly.
Example:
Compiler_Test.cpp source code
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CaN AS. Tal CaS aS OAS
// Filename: Compiler_Test.cpp
// Purpose: Average the ages of two people
// Author: Ken Busbee; © Kenneth Leroy Busbee
// Date: Jane 5, 2009
// Comment: Main idea is to be able to
a debug and run a program on your
compiler.
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// Headers and Other Technical Items
#include <iostream>
uSing namespace std;
// Function Prototypes
void pause(void);
// Nariables
Bel Ayle age1;
int aqe2,
double answer;
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Ceo Be ee See
// main
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int main(void)
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cout << "\nEnter the age of the first person ---
te ae
Cin >> age;
cout << "\nEnter the age of the second person --
Bae ee
Cin >> age2;
// Process
answer = (ageil + age2) / 2.0;
// Output
cout << "\nThe average of their ages is --------
= Wa
y
cout << answer;
pause();
return 0;
}
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KKKKKK
// pause
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KKEKKKK
void pause(void)
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cout << "Nan;
system("PAUSE");
Cour << "\ANn”
return;
}
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// End of Program
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KAKA Wek.
Within the programming industry there is a desire to make software
programs easy to maintain. The desire centers in money. Simply put, it costs
less money to maintain a well written program. One important aspect of
program maintenance is making source code listings clear and as easy to
read as possible. To that end we will consider the following:
1. Documentation
2. Vertical Alignment
3. Appropriate use of Comments
4. Banners for Functions
5. Block Markers on Lines by Themselves
6. Indent Block Markers
7. Meaningful Identifier Names Consistently Typed
8. Appropriate use of Typedef
The above items are not needed in order for the source code to compile.
Technically the compiler does not read the source code the way humans
read the source code. But that is exactly the point; the desire is to make the
source code easier for humans to read. You should not be confused between
what is possible (technically will compile) and what is ok (acceptable good
programming practice that leads to readable code). Let's cover each item in
more detail.
Documentation
Documentation is usually placed at the top of the program using several
comment lines. The amount of information would vary based on the
requirements or standards of the company who is paying its employees or
independent contractors to write the code. Notice the indication of revision
dates.
Vertical Alignment
You see this within the documentation area. All of the items are aligned up
within the same column. This vertical alignment occurs again when the
variables are defined. When declaring variable or constants many textbooks
put several items on one line; like this:
Example:
Common Textbook Defining of Variables
float length, width, height, price_gal_paint,
total_area, total_cost;
int coverage_gal_paint, total_gal_paint;
However common this is in textbooks, it would generally not be acceptable
to standards used in most companies. You should declare each item on its
own line; like this:
Example:
Proper Defining of Variables with Vertical Alignment
float length;
float width;
float height;
float price_gal_paint;
int coverage_gal_paint;
float total_area;
aL qie Eatalogal paint:
float total-cost;
This method of using one item per line is more readable by humans. It is
quicker to find an identifier name, because you can read the list vertically
faster than searching horizontally. Some programmers list them in
alphabetic order, especially when the number of variables exceeds about
twenty.
The lines of code inside either function are also aligned vertically and
indented two spaces from the left. The indentation helps set the block off
visually.
Appropriate use of Comments
You can see through the source code short little comments that describe an
area or section. Note the use of input, processing and output which are part
of the IPO concept within the program design.
Banners for Functions
Note the use of comments in the form of a banner before each function.
Example:
Comments as a Banner
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IE ee a
// main
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KKKKKK
The function name is placed with two lines of asterisks. It makes it
extremely easy to find each function definition because you don’t have to
read the functions to see where the one ends and the next one begins. You
can quickly read the function names within the banners.
Block Markers on Lines by Themselves
Within many languages there is a method to identify a group of
programming statements as a unit. With C++ the functions use a set of
symbols, the braces {}, to identify a block of code, sometimes referred to as
a compound statement. Braces are used in other aspects of programs, but
for now we will look at this simple example. These braces have a tendency
to cause problems, especially when they don’t have a proper opening brace
associated with a proper closing brace. To solve that problem many
programmers simply put a brace on a line by itself and make sure the
opening brace and closing brace are in the same vertical column.
Indent Block Markers
A block of code associated with a function or with a control structure is
indented two or three spaces. When blocks of code are nested each nesting
is indented two or three spaces. In our example above the blocks of code for
the function definitions are indented two spaces.
Meaningful Identifier Names Consistently Typed
As the name implies "identifier names" should clearly identify who (or
what) you are talking about. Calling you spouse "Snooky" may be
meaningful to only you. Others might need to see her full name (Jane Mary
Smith) to appropriately identify who you are talking about. The same
concept in programming is true. Variables, constants, functions, typedefs
and other items should use meaningful identifier names. Additionally, those
names should be typed consistently in terms of upper and lower case as they
are used in the program. Don't define a variable as: Pig and then type it later
on in your program as: pig.
Appropriate use of Typedef
Many programming languages have a command that allows for the creation
of an identifier name that represents a data type. The new identifier name is
described or connected to a real data type. This feature is not demonstrated
in the code above and is often a confusing concept. It is a powerful way to
help document a program so that it is meaningful, but is often used by more
experienced programmers.
Definitions
documentation
A method of preserving information useful to others in understanding
an information system or part thereof.
vertical alignment
A method of listing items vertically so that they are easier to read
quickly.
comments
Information inserted into a source code file for documentation of the
program.
banners
A set of comment lines used to help separate the functions and other
sections of a program.
braces
Used to identify a block of code in C++.
indention
A method used to make sections of source code more visible.
meaningful
A rule that says identifier names must be easily understood by another
reading the source code.
consistent
A rule that says to type identifier names in upper and lower case
consistently throughout your source code.
Practice 6: Program Control Functions
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Given pseudocode, test data and source code of an existing program,
modify the pseudocode and source code to create "program control"
functions.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Pseudocode has a strict set of rules and is the same everywhere in
the computer programming industry.
2. Hierarchy Charts and Structure Charts are basically the same
thing.
3. Program Control functions are used to simply sub divide and
control the program.
4. The void data type is rarely used in C++.
5. Making source code readable is only used by beginning
programmers.
Solution:
Answers:
1. false
2. true
3. true
4. false
5. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 06 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_06 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Solution Lab O1.cpp
Download from Connexions: Solution Lab 01 Pseudocode.txt
Download from Connexions: Solution Lab 01 Test Data.txt
Download from Connexions:
Solution Lab 01m with Program Control.cpp
Download from Connexions:
Solution Lab 01m Pseudocode with Program Control.txt
Download from Connexions: Solution Lab 01m Hierarchy_Chart.jpg
Download from Connexions: Solution Lab 03.cpp
Download from Connexions: Solution Lab 03 Pseudocode.txt
Download from Connexions: Solution Lab 03 Test Data.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Navigate to your sub-folder: Chapter_06. Review the original Lab 01
materials. Compile and run the Lab 01 source code. Then review and
compare the original Lab 01 materials to modularized Lab 01 materials
taking note of the conversion to "program control" functions. Compile
and run the Lab 01m source code. Review as needed the course
materials. Email your professor if you have any questions.
¢ We have supplied the solution to the Lab 03 assignment. Review the
Lab 03 assignment by compiling and running the Lab 03 source code.
e You need to copy the Lab 03 source code file and pseudocode file to
make the following new files: Lab_06.cpp and
Lab_06_Pseudocode.txt
¢ Modify the Lab 06 pseudocode file to implement “program control”
functions as shown in the demonstration materials.
e Modify the Lab 06 source code file to implement “program control”
functions as shown in the demonstration materials.
¢ Build (compile and run) your program. You have successfully written
this program if when it runs and you use the test data [use the same test
data as used in Lab 03] it gives the same results as Lab 03.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 06a — Instructions
Create a hierarchy chart for the following pseudocode example.
Example:
pseudocode
ROKR IRR KEK ERR ROKR KKK RRA RIK RR KKK RK RK KER KARR KR KARR RAK KK RE KX
KKKX
Filename: Average_IQ.txt
Purpose: Average the IQs of two people
Author: Ken Busbee; © Kenneth Leroy Busbee
Date: Jani, 2009
KOKER KR KK KIRK KR ERK EK KR KR KEK KX KER KE KX RRR KE KKK ER EKER KEK KEK KR E KX
CASAS SAY CAS
Function main
Pass In: nothing
Call: get_igqs
Call: process_iqs
Call: show_average
Pass Out: zero to the OS
Endfunction
KEKEKKKKKKKRKEKRKEKEKKEKEKEE
Function get_iqs
Pass In; norhing
display a message asking user for the IQ of the
first person
get the IQ of the first person from the keyboard
display a message asking user for the IQ of the
second person
get the IQ of the second person from the
keyboard
Pass Out: nothing
Endfunction
CaS PAS Lad Pal Zab iad ad Ay Pal aT aS PAN Ad Tad Gat SAS Cah ah Zab Za
Function process_iqs
Pass In: nothing
calculate the answer by adding the two IQs and
oak Wak olt ale) lehy 72518)
Pass Out: nothing
Endfunction
KKK RRR RK KR ROKR RR KR KER RR KX
Function show_average
Pass In: nothing
display the answer with an appropriate message
Call: pause
Pass Out: nothing
Endfunction
KEK ROKUARAR OK ROKR RR RR Ra ae
Function pause
Pass In: nothing
direct the operating system to pause the program
Pass Out: nothing
Endfunction
ROKK KER KOR KORA KOR ROKR AR RI KR RR ROR KR ROKR RR OREK CLR ORRICK ee eek
KER
Potential Variables
Data Type Identifier Name
Kok Ke we Kak eK KIX Kaw Roe AOA ae OK
integer igi
integer 1iq2
double answer
KEK KORO RAE KER RI RE REO HK KEKE RR RAE RE RR KOR KERR KR KEKE IRE RK REA KOK KOREREREX,
Pas AS Lad Pas
End of file
Problem 06b — Instructions
W
Identify some problems that make this code "undocumented", "unreadable
or wrong in some other way.
Example:
C++ source code
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// Author: Ken Busbee; © 2009 Kenneth Leroy
Busbee
// Date: Jan 17, 2009
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#include <iostream>
uSing namespace std;
void pause(void);
ane agel, age2;
double xx:
KEK KARE,
// main
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int main(void)
{
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cout << "\nEnter the age of the first person --->:
Wa
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Cin >> age1;
cout << "\nEnter the age of the second person
Sect ae
Cin >> age2;
// Process
XxX = (agel + age2) / 2.0;
7/7 OUEDUE
cout << "\nThe average of their ages is --------
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COU <= xXx;
pause () :
+
return 0;
Specific Task Functions
A general explanation of specific task functions.
Prerequisite Material
Critical to this module is the review of two Connexions modules:
1. m_18861 — Titled: Modularization and C++ Program Layout
2.m_19145 — Titled: Program Control Functions
You should review these materials before proceeding. If you are viewing
this module on-line, links to these items are in the "Links" box to your right.
General Concept
Program Control functions which might have similar identifier names
usually perform slightly different tasks in one program to another. Looking
at the organizational chart or hierarchy chart for two companies, both might
have a vice president of production, but producing automobiles is different
than producing ice cream. Similar but different. As you go down deeper
into an organization you might find the job title of security guard. Notice
that the security guard at the automobile plant and the security guard at the
ice cream plant have exactly the same job. In fact, they are most likely
interchangeable. Within programming when a task gets specific it might be
useable in several programs. The calculation of leap year is a good
example. Needed for the verification of dates, is there or is there not a 2gth
of February for this year. Needed in thousands of programs.
Specific Task Functions
To create good Specific Task functions you need to do all communication
needed via parameter passing. Thus all programs that will use the function
will communicate in precisely the same way. In our leap year example, you
would communicate into the function the year and the function would
return the communication of true or false; meaning it is a leap year and
there is a 29" of February (true) or it is not a leap year (false).
The ability to modularize our program into specific task functions means
that we can write the specific task function once making sure it works
correctly, then reuse it over and over in many programs. As you can guess
there is a balance. Most programs will have some program control functions
and some specific task functions. The key to deciding if the function should
be a specific task function is usually rooted in the uniqueness of the task so
that it can be used in many programs. Specific task functions once created
are usually placed into a user defined library then shared with others for
use in many programs.
Definitions
user defined library
A file containing specific task functions created by individuals to be
used in many programs.
Global vs Local Data Storage
A explanation of scope and its effect on data storage and its use in
modularization.
General Discussion
The concept of global and local data storage is usually tied to the concept of
scope. Scope is the area of the program where an item (be it variable,
constant, function, etc.) that has an identifier name is recognized. In our
discussion we will use a variable and the place within a program where the
variable is defined determines its scope.
Global scope (and by extension global data storage) occurs when a variable
is defined "outside of a function". When compiling the program it creates
the storage area for the variable within the program's data area as part of
the object code. The object code has a machine code piece, a data area and
linker resolution instructions. Because the variable has global scope it is
available to all of the functions within your source code. It can even be
made available to functions in other object modules that will be linked to
your code; however we will forgo that explanation now. A key wording
change should be learned at this point. Although the variable has global
scope, technically it is available only from the point of definition to the
end of the program source code. That is why most variable with global
scope are placed near the top of the source code before any functions. This
way they are available to all of the functions.
Local scope (and by extension local data storage) occurs when a variable is
defined "inside of a function". When compiling, the compiler creates
machine instructions that will direct the creation of storage locations on an
area known as the stack which is part of the computer's memory. These
memory locations exist until the function completes its task and returns to
its calling function. In assembly language we talk about items being pushed
onto the stack and popped off the stack when the function terminates. Thus,
the stack is a reusable area of memory being used by all functions and
released as functions terminate. Although the variable has local scope,
technically it is available only from the point of definition to the end of
the function. The parameter passing of data items into a function
establishes them as local variables. Additionally, any other variables or
constants needed by the function usually occur near the top of the function
definition so that they are available during the entire execution of the
function's code.
Scope is an important concept to modularization. Program Control
functions usually use global scope for variables and constants placing them
near the top of the program before any functions. Specific Task functions
use only local scope variables by passing data as needed into the function
with parameter passing and creating local variables and constants as
needed. Any information that needs to be communicated back to the calling
function is again done via parameter passing. This closed communications
model that passes all data into and out of a function creates an important
predecessor concept for encapsulation which is used in object oriented
programming.
Definitions
global scope
Data storage defined outside of a function.
local scope
Data storage defined inside of a function.
data area
A part of an object code file used for storage of data.
stack
A part of the computer's memory used for storage of data.
scope
The area of a source code file where an identifier name is recognized.
Using a Header File for User Defined Specific Task Functions
Concepts and an example of how to create a user library within the C++
programming language.
Concept: User Defined Specific Task Functions
Most companies have certain tasks that are unique to their company.
Collectively the programming staff may decide to build several functions
and organize them into one or more user libraries. Specific task functions
are often built using a testing shell program. The sole purpose of the testing
shell program is to create the specific task functions and to test them to
insure that they are working properly. Think of a clam, its shell surrounds
the important part, the pearl. A testing shell program surrounds the specific
task function (the important part). Usually the testing shell program will be
used to create several functions that will be placed into a user defined
library. The process flows as follows:
1. The testing shell program with the specific task functions is built and
thoroughly tested.
2. A copy of the testing shell source code is saved as the header file that
once modified will be placed in the user library. You delete the main
part of the program leaving a comments area, any needed include file
references and the specific task functions.
Header File Creation
Monitor_Testing_Shell.cpp
Program Comments
Headers & Other
Prototypes
Variables
main
clear_m
delay_m
pause_m
udst_monitor.h
ProgramComments Edit as appropriate
Headers & Other Delete all but needed
libraries. Keep: #include <ctime>
Protetypes
Variables
PH
clear_m
delay_m the clock function needs: ctime
pause_m
Creating a header file from a copy of the testing shell.
3. Another copy of the testing shell source code is saved as the
prototypes file. This is a text file that retains only the prototypes for
the functions that were placed into the header file. The functions
should be using meaningful identifier names, thus the prototypes
should provide adequate information to others on how to call the
function with appropriate parameter passing.
Prototypes File Creation
Monitor_Testing_Shell.cpp udst_monitor_prototypes.txt
Program Comments ProgramComments Edit as appropriate
Headers & Other Headers & Other
Prototypes Prototypes
Variables Meibtas
main AHH
clear_m clears
delay_m delay
pause_m Pitch
Creating a prototypes file from a copy of the testing shell.
4. Another copy of the testing shell source code is saved as the verify
header program. You delete the functions prototypes and definitions
then provide an include that points to the header file. This program is
compiled and run to make sure the header file is working properly.
Verify Header File Creation
Monitor_Testing_Shell.cpp Monitor_Verify_Header.cpp
Program Comments Program Comments Edit as appropriate
Headers & Other Headers & Other Add user libraries as needed:
#include “c:\\Dev-Cpp\\user_library\\monitor.h”
Prototypes Prototypes
Variables Variables
main main
clear_m clean
delay_m delay
pause_m freee
Creating a verify header file from a copy of the testing shell.
A good way to understand the concept is to review the four files described
above that have been created by a programmer. We will be using the C++
programming language, however the code is easy to understand and will
serve our needs well at explaining the concepts; even if you are not familiar
with C++.
Demonstration Using C++
Creating a Folder or Sub-Folder for the Four Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Monitor Header
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Four Files
Download and store the following files to your storage device in the
appropriate folder. You may need to right click on some of the links and
select "Save Target As" in order to download some of the files.
Download from Connexions: Monitor Testing Shell.cpp
Download from Connexions: udst_monitor.h
Download from Connexions: udst_monitor_prototypes.txt
Download from Connexions: Monitor Verify Header.cpp
Study the Files Collectively to Understand the Concepts
Take a few moments to review the files in conjunction with the concept
discussion above. You should compile and run the
Monitor_Testing_ Shell.cpp program.
Creating a Folder or Sub-Folder for your User Library
Depending on your compiler/IDE, you should decide where to create a
folder that will hold the header files you create. We suggest that you create
the folder in conjunction with the compiler/IDE software. If you were using
the Bloodshed Dev-C++ 5 compiler/IDE you most likely installed the
compiler/IDE software at: C:\Dev-Cpp\ if you installed it on your machine
or at: DriveLetter:\Dev-Cpp\ (where the DriveLetter is the drive that
represents your flash drive) if you installed it on a flash drive. We suggest
that you create a sub-folder at that location named:
e user_library
The path of: C:\Dev-Cpp\user_library would be created as the location for
your user library if using your machine installation. You can literally place
it anywhere and name the library any name, but once you decide on a place
and name; you do not want to move or rename the folders.
Placing the Header File into the User Library
You need to copy the udst_monitor.h file placing it into the user_library
folder just created. As you can guess the udst stands for user defined
specific task. The functions within this header file would be used to control
the interaction a user has with the monitor. The .h is a convention of the
C++ programming language and indicates a header file. Thus the identifier
name for the header file is very meaningful and descriptive.
Verify that the Header File Works Properly
Review the Monitor_Verify_Header.cpp source code file and note the two
include commands are different.
1. The Standard Library uses a less than and a greater than to bracket the
Standard Library name of: iostream
2. The user library uses quote marks to bracket the location of the header
file. This identifies to the complier that we are specifying the exact file
we want. We provide a complete file specification (drive, path
information, filename and extension).
3. Because this item is technically a string within C++, we must use two
back slashes between the drive, path(s) and filename. This is because
the first back slash assumes that the next character is an escape code
and if we really don't want an escape code but a back slash, the second
back slash says no I wanted a back slash.This string: "C:\\Dev-
Cpp\\user_library\\udst_monitor.h" will be interpreted to mean:
C:\Dev-Cpp\user_library\udst_monitor.h
Depending on what drive you are using, what path folder structure you are
using and what you called your folder; you may need to correct the include
reference within the source code so that it properly references the header
file.
Compile and run the Monitor_Verify_Header.cpp program. Note: It should
work exactly as the Monitor_Testing_Shell.cpp program.
Definitions
udst
User Defined Specific Task
testing shell
A program used to create specific task functions.
header file
A file that contains items we want to have included toward the top of
our source code.
Practice 7: Specific Task Functions
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Given a testing shell program already coded and tested, create a user
defined specific task header file, a user defined specific task prototypes
document and a source code program to verify that the header file
works properly.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Scope refers to a brand of mouth wash.
2. User defined specific task functions are usually placed into a user
defined library.
3. Local and global data storage is associated with the concept of
scope.
4. Creating a header file for user defined specific task functions is a
difficult task.
5. The stack is part of the computer’s memory used for storage of
data.
Solution:
Answers:
1. false — Although Scope is a brand of mouth wash; we are looking
for the computer related definition.
2. true
3. true
4. false — It may seem difficult at first, but with a little practice it is
really quite easy.
9. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 07 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_07 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_07 Testing Shell.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Navigate to your sub-folder: Chapter_07. Compile and run the Lab 07
Testing Shell source code. Note: This program uses an include file that
points to the "udst_monitor.h" file as explained in Connexions Chapter
7 materials.
e Following same process as shown in the Connexions module "Using a
Header File for User Defined Specific Task Functions" that is within
the Chapter 7 materials; make the following files:
udst_us_to_metric.h and udst_us_to_metric_prototypes.txt and
Lab_07_Verify_Header.cpp
¢ Copy the header file to your user library, then build (compile and run)
your verify header program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 07a — Instructions
Create the pseudocode to solve the following specific task function:
Problem: An interior designer always needs to calculate the area of a room
to determine the amount of floor covering needed (usually carpet). The
rooms are rectangular with the dimensions measured in feet (with decimal
fractions). The function however needs to return square yards. Hint: There
are 3 lineal feet to a yard.
Problem 07b — Instructions
Create test data for the following specific task function:
Problem: An interior designer always needs to calculate the area of a room
to determine the amount of floor covering needed (usually carpet). The
rooms are rectangular with the dimensions measured in feet (with decimal
fractions). The function however needs to return square yards. Hint: There
are 3 lineal feet to a yard.
Standard Libraries
A general discussion of Standard Libraries with a demonstration program in
C++ and an attachment containing other standard C++ library information.
Overview of Standard Libraries
Many common or standard functions, whose definitions have been
written, are ready to be used in any program. They are organized into a
group of functions (think of them as several books) and are collectively
called a Standard Library There are many function organized into several
libraries For example, within C++ many math functions exist and have been
coded (and placed into libraries). These functions were written by
programmers and tested to insure that they work properly. In most cases the
functions were reviewed by several people to double and triple check to
insure that they did what was expected. We have the advantage of using
these functions with confidence that they will work properly in our
programs, thus saving us time and money.
A main program must establish the existence of functions used in that
program. Depending on the programming language, there is a formal way
to:
1. define a function
2. declare a function (a prototype is a declaration to a compiler)
3. call a function
When we create functions in our program, we usually see them in the
following order in our source code listing:
1. declare the function (prototype)
2. call the function
3. define the function
When we use functions created by others that have been organized into
library, we include a header file in our program which contains the
prototypes for the functions. Just like functions that we create, we see them
in the following order in our source code listing:
1. declaring the function (prototype provided in the include file)
2. call the function (with parameter passing of values)
3. define the function (it is either defined in the header file or the linker
program provides the actual object code from a Standard Library
object area)
In most cases, the user can look at the prototype and understand exactly
how the communications (parameter passing) into and out of the function
will occur when the function is called. Let's look at the math example of
absolute value. The prototype is:
int abs(int number);
Not wanting to have a long function name the designers named it: abs
instead of "absolute". This might seem to violate the identifier naming rule
of using meaningful names, however when identifier names are established
for standard libraries they are often shortened to a name that is easily
understood by all who would be using them. The function is of data type
int, meaning that the function will return an integer value. It is obvious that
the integer value returned is the answer to the question, "What is the
absolute value of the integer that is being passed into the function". This
function is passed only one value; an int number. If I had two integer
variables named apple and banana; and I wanted to store the absolute value
of banana into apple; then a line of code to call this function would be:
apple = abs(banana);
Let's say it in English, pass the function absolute the value stored in
variable banana and assign the returning value from the function to the
variable apple. Thus, if you know the prototype you can usually properly
call the function and use its returning value (if it has one) without ever
seeing the definition of the code (i.e. the source code that tells the function
how to get the answer; that is written by someone else; and either included
in the header file or compiled and placed into an object library; and linked
during the linking step of the Integrated Development Environment (IDE).
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on some of the links and
select "Save Target As" in order to download some of the files. Following
the methods of your compiler/IDE, compile and run the program(s). Study
the source code and/or other file(s) in conjunction with other learning
materials.
Download from Connexions: Demo Standard _Libraries.cpp
Download from Connexions: Demo Standard Libraries Listing.txt
Definitions
Standard Library
A set of specific task functions that have been added to the
programming language for universal use.
confidence
The reliance that Standard Library functions work properly.
abs
A function within the cmath standard library in C++ which stands for
absolute.
Practice 8: Standard Libraries
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Given a testing shell program already coded and tested, add another
specific task function, and test it, then create a user defined specific
task header file, a user defined specific task prototypes document and a
source code program to verify that the header file works properly.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. The standard library is a set of specific task functions that have
been added to the programming language for universal use.
2. Programmers should not have confidence that standard library
functions work properly.
3. It would be easier to write programs without using specific task
functions.
Solution:
Answers:
1. true
2. false
3. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 08 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_08 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab 08 Testing Shell.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Navigate to your sub-folder: Chapter_08. Compile and run the Lab 08
Testing Shell source code. Note: This program uses an include file that
points to the "udst_monitor.h" file as explained in Connexions Chapter
7 materials.
e You need to add another function to this testing shell titled:
area_triangle that is to calculate the area of a triangle. Define the
function, prototype it, and within the function main add an area for
calling the function (similar to the existing functions with test data).
Be confident that it is working properly.
e Following same process as shown in the Connexions module "Using a
Header File for User Defined Specific Task Functions" that is within
the Chapter 7 materials; make the following files: udst_geo_area.h
and udst_geo_area_prototypes.txt and Lab_08_Verify_Header.cpp
¢ Copy the header file to your user library, then build (compile and run)
your verify header program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 08a — Instructions
Write the C++ code to do the following specific task function.
Example:
pseudocode
Function area_regular_hexagon
Pass In:
Character Data Type
An introduction to the character data type.
Overview of the Character Data Type
The character data type basically represents individual or single characters.
Characters comprise a variety of symbols such as the alphabet (both upper
and lower case) the numeral digits (0 to 9), punctuation, etc. All computers
store character data in a one byte field as an integer value. Because a byte
consists of 8 bits, this one byte field has 28 or 256 possibilities using the
positive values of 0 to 255.
Most microcomputers use the ASCII (stands for American Standard Code
for Information Interchange and is pronounced "ask-key") Character Set
which has established values for 0 to 127. For the values of 128 to 255 they
usually use the Extended ASCII Character Set. When we hit the capital A
on the keyboard, the keyboard sends a byte with the bit pattern equal to an
integer 65. When the byte is sent from the memory to the monitor, the
monitor converts the integer value of 65 to into the symbol of the capital A
to display on the monitor.
The character data type attributes include:
C++
Reserved char
Word
Represent Single characters
Size 1 byte
Normal Unsigned (positive values only)
Signage
Domain Values from 0 to 127 as shown in the standard ASCII
(Values Character Set, plus values 128 to 255 from the
Allowed) Extended ASCII Character Set
C++
syntax Single quote marks — Example: 'A'
rule
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the soruce code file(s) in
conjunction with other learning materials.
Definitions
character
A data type representing single text characters like the alphabet,
numeral digits, punctuation, etc.
ASCII
American Standard Code for Information Interchange
single quote marks
Used to create character type data within the C++ programming
language.
Sizeof Operator
An explanation of the sizeof operator with examples as used within the C++
programming language.
Overview
Every data item, constants and variables, not only have a data type, but the
data type determines how many bytes the item will use in the memory of
the computer. The size of each data type varies with the complier being
used and the computer. This effect is known as being machine dependent.
Additionally, there have been some size changes with upgrades to the
language. In "C" the int data type was allocated 2 bytes of memory storage
on an Intel compatible central processing unit (cpu) machine. In "C++" an
int is allocated 4 bytes.
There is an operator named "sizeof (... )" that is a unary operator, that is it
has only one operand. The operand is to the right of the operator and is
placed within the parentheses if it is a data type. The operand may be any
data type (including those created by typedef). If the operand is an identifier
name it does not need to go inside a set of parentheses. It works for both
variable and memory constant identifier names. This operator is unique in
that it performs its calculation at compile time for global scoped items and
at run time for local scoped items. Examples:
cout << "The size of an integer is: " << sizeof
(nie);
The compiler would determine the byte size of an integer on the specific
machine and in essence replaces the sizeof operator with a value. Integers
are usually 4 bytes long, thus the line of code would be changed to:
COuUle <<" ihe Size Of ahednteger 15, 9 <<) 4)
If you place an identifier name that represents a data storage area (variable
or Memory constant), it looks at the definition for the identifier name.
NOTE: the parentheses are not needed and often not included for an
identifier name.
Example:
sizeof with a Variable
double money; // variable set up with
inatlalazacion
then later on in the program
cout << "The size of money is: " << sizeof money;
The compiler would determine the byte size of money by looking at the
definition where it indicates that the data type is double. The double data
type on the specific machine (usually 8 bytes) would replace the code and it
would become:
cout << "The size of money is: " << 8;
Definitions
sizeof
An operator that tells you how many bytes a data type occupies in
storage.
Typedef - An Alias
An explanation of typedef being used to create an alias data type.
General Discussion
The typedef statement allows the programmer to create an alias, or
synonym, for an existing data type. This can be useful in documenting a
program. The C++ programming language syntax is:
typedef <the real data type> <the alias identifier
name>;
Let's say a programmer is using a double data type to store the amount of
money that is being used for various purposes in a program. He might
define the variables as follows:
Example:
Regular Definition of Variables
double income;
double rent;
double vacation;
However, he might use the typedef statement and define the variables as
follows:
Example:
Using typedef when Defining Variables
typedef double cash;
the typedef must be defined before its use
cash income;
cash rent;
cash vacation;
The typedef statement is not used very often by beginning programmers. It
usually creates more confusion than needed, thus stick to using the normal
data types at first.
Definitions
typedef
Allows the programmer to create an alias, or synonym, for an existing
data type.
Sequence Operator
Outlines several uses of the sequence operator within the C++ programming
language.
General Discussion
The sequence (or comma) operator is used to separate items. It has several
uses, four of which are listed then demonstrated:
1. To separate identifier names when declaring variables or constants
2. To separate several parameters being passed into a function
3. To separate several initialization items or update items in a for loop
4. Separate values during the initialization of an array
This first example is often seen in textbooks, but this method of declaring
variables is not preferred. It is difficult to quickly read the identifier names.
Tie PIG, COG); Cab, kak,
The following vertical method of declaring variables or constants is
preferred.
Example:
Preferred Vertical Method of Defining Variables
Ln. pig)
Int. Saoge
ne “CAE;
iit Rae:
The data types and identifier names (known as parameters) are separated
from each other. This example is a function prototype.
double area_trapezoid(double base, double height,
double top);
In the syntax of a for loop you have three parts each separated by a semi-
colon. The first is the initialization area which could have more than one
initialization. The last is the update area which could have more than one
update. Mutiple initializations or updates use the comma to separate them.
This example is only the first line of a for loop.
fone ya, et xe
The variable ages is an array of integers. Initial values are assigned using
block markers with the values separated from each other using a comma.
iitaages =e ed eorconoe
Definitions
sequence
An operator used to separate multiple occurrences of an item.
Practice 9: Character Data, Sizeof, Typedef, Sequence
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Given appropriate documents produced by a System Analyst, create
planning documents (pseudocode and test data), then a source code
program that accomplishes the goals of the program.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. The character data type in C++ uses the double quote marks, like:
char grade = "A";
2. Sizeof is an operator that tells you how many bytes a data type
occupies in storage.
3. Typedef helps people who can't hear and is one of the standard
accommodation features of a programming language for people
with a learning disability.
4. The sequence operator should be used when defining variables in
order to save space.
5. Programming can be both enjoyable and frustrating.
Solution:
Answers:
1. false
2. true
3. false
4. false
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 09 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_09 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_09 Narrative Description.txt
Download from Connexions:
Lab_09 Aerial View Center Pivot Irrigation.jpg
Download from Connexions: Lab_09 Hierarchy Chart.jpg
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Review the Connexions module "Systems Development Life Cycle"
within the Chapter 1 materials. Think of yourself as a programmer
assigned to a project during the Implementation phase with your
professor as the System Analyst.
e Navigate to your sub-folder: Chapter_09. Review the first two items
provided by the system analyst which he produced during the Design
phase of the Systems Development Life Cycle. These two documents
historically would have been printed and be placed into a program
documentation folder. The items you produce in creating the program
would be added to the folder. However, shifting to our paperless view
of the world, today these items might be created and stored
electronically in electronic folders (which is basically what we are
doing by using our sub-folder titled: Chapter_09). The third item, the
hierarchy chart, would normally be produced by the programmer.
However, given your inexperience, the system analyst has created it
for you. Make sure you understand what the program is to do. Any
questions ask the system analyst (aka your professor).
Note:The narrative description for this lab assignment describes how
farmers in the mid-west part of the United States irrigate a piece of land
using a circular irrigation system. This practice also known to as center
pivot irrigation is not unique to the United States. Google "map Qatar",
click on the map and switch to the "Satellite" view, zoom in and notice that
there are several spots in this small middle eastern country where this type
of irrigation is being used. "These systems are found and used in all parts
of the world..." which supports the appropriateness of this programming
problem to all students.
e Design the program and create your test data by building a
Lab_09_Pseudocode.txt file and a Lab_09_Test_Data.txt file.
WARNING: Don't touch the compiler/IDE. Don't start by creating the
source code file. Creating the source code then producing the planning
documentation afterwards is a bad habit that beginning programmers
often acquire. NOTE: In your pseudocode document you do not need
to create any pseudocode for the Standard Library or User Library
functions. Just indicate that you call them from the Program Control
functions. If needed, review the Connexions module "Pseudocode
Examples for Functions" within the Chapter 6 materials. HINT:
Copying the pseudocode and test data files from the Chapter 06 folder
might be a good way to start building these items.
e After you have successfully planned the document and created your
test data; create the source code file naming it: Lab_09.cpp HINTS:
Using a previous source code file as your starting file makes sense.
The file in the Chapter 06 folder might be a good start. You might want
to copy some of the include information from the Verify Header code
in Chapter 08 into your Lab 09 source code file.
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 09a — Instructions
The sequence operator can be used when declaring multiple identifier
names for variables or constants of the same data type. Is this a good or bad
programming habit and why?
Structured Programming
An introduction to control structure categories and those allowed in
structured programming.
Introduction
One of the most important concepts of programming is the ability to control
a program so that different lines of code are executed or that some lines of
code are executed many times. The mechanisms that allow us to control the
flow of execution are called control structures. Flowcharting is a method
of documenting (charting) the flow (or paths) that a program would
execute. There are four main categories of control structures:
e Sequence — Very boring. Simply do one instruction then the next and
the next. Just do them in a given sequence or in order listed. Most lines
of code are this.
¢ Selection — This is where you select or choose between two or more
flows. The choice is decided by asking some sort of question. The
answer determines the path (or which lines of code) will be executed.
e Iteration — Also known as repetition, it allows some code (one to
many lines) to be executed (or repeated) several times. The code might
not be executed at all (repeat it zero times), executed a fixed number of
times or executed indefinitely until some condition has been met. Also
known as looping because the flowcharting shows the flow looping
back to repeat the task.
¢ Branching — A control structure that allows the flow of execution to
jump to a different part of the program. This category is rarely used in
modular structured programming.
All high-level programming languages have control structures. All
languages have the first three categories of control structures (sequence,
selection, and iteration). Most have the if then else structure (which belongs
to the selection category) and the while structure (which belongs to the
iteration category). After these two basic structures there are usually
language variations.
The concept of structured programming started in the late 1960's with an
article by Edsger Dijkstra. He proposed a "go to less" method of planning
programming logic that eliminated the need for the branching category of
control structures. The topic was debated for about 20 years. But ultimately
— "By the end of the 20th century nearly all computer scientists were
convinced that it is useful to learn and apply the concepts of structured
programming. "[footnote]
Structured programming from Wikipedia
Introduction to Selection Control Structures
The basic attribute of a selection control structure is to be able to select
between two or more alternate paths. This is described as either two-way
selection or multiway selection. A question using Boolean concepts
usually controls which path is selected. All of the paths from a selection
control structure join back up at the end of the control structure, before
moving on to the next lines of code in a program.
We have mentioned that the if then else control structure belongs to the
selection category and is a two-way selection.
Example:
if then else control structure
if (age = 17)
cout << "You can vote.";
}
else
{
COUL << “YOU cal & vove. 7
i
Introduction to Iteration Control Structures
The basic attribute of an iteration control structure is to be able to repeat
some lines of code. The visual display of iteration creates a circular loop
pattern when flowcharted, thus the word "loop" is associated with iteration
control structures. Iteration can be accomplished with test before loops,
counting loops, and test after loops. A question using Boolean concepts
usually controls how long the loop will execute.
We have mentioned that the while control structure belongs to the iteration
category and is a test before loop.
Example:
while control structure
counter = 0;
while (counter < 5)
{
cout << "\nI love computers!";
counter ++;
i
Definitions
control structures
Mechanisms that allow us to control the flow of execution within a
program.
sequence
A control structure where you do the items in the sequence listed.
selection
A control structure where you select between two or more choices.
iteration
A control structure that allows some lines of code to be executed many
times.
branching
A control structure that allows the flow of execution to jump to a
different part of the program.
structured programming
A method of planning programs that avoids the branching category of
control structures.
Pseudocode Examples for Control Structures
Pseudocode conventions and control structure examples of: if then else,
case, while, for, do while and repeat until.
Overview
No standard for pseudocode syntax exists. However, there are some
commonly followed conventions to help make pseudocode written by one
programmer easily understood by another programmer. Most of these
conventions follow two concepts:
e Use indentation to show the action part of a control structure
e Use an ending phrase word to end a control structure
The sequence control structure simply lists the lines of pseudocode. The
concern is not with the sequence category but with selection and two of the
iteration control structures. The following are commonly used ending
phrase-words:
Control Structure Ending Phrase Word
If then Else Endif
Case Endcase
While Endwhile
For Endfor
The Do While and Repeat Until iteration control structures don't need an
ending phrase-word. We simply use the first word, then the action part,
followed by the second word with the test expression. Here are some
examples:
Selection Control Structures
Example:
pseudocode: If then Else
If age > 17
Display a message indicating you can vote.
Else
Display a message indicating you can't vote.
Emo int
Example:
pseudocode: Case
Case of age
O to: 17 Display "You can't vote."
18 to 64 Display "You're in your working
years."
Oar Display "You should be retired."
Endcase
Iteration (Repetition) Control Structures
Example:
pseudocode: While
count assigned zero
While count < 5
Display "I love computers!"
Increment count
Endwhile
Example:
pseudocode: For
For x starts at 0, x < 5, increment x
Display "Are we having fun?"
Endfor
Example:
pseudocode: Do While
count assigned five
Do
Display "Blast off 1s soon!"
Decrement count
While count > zero
Example:
pseudocode: Repeat Until
count assigned five
Repeat
Display “Blast off 1s soon!”
Decrement count
Until count < one
Flowcharting
An introduction to flowcharting including the demonstration of functions
and various control structures.
Flowcharting Symbols
Terminal
The rounded rectangles, or terminal points, indicate the flowchart's starting
and ending points.
Process
The rectangle depicts a process such as a mathematical computation, or a
variable assignment.
Note: the C++ language equivalent is the statement.
Input/Output
The parallelograms designate input or output operations.
Note: the C++ language equivalent is cin or cout.
Connectors
Sometimes a flowchart is broken into two or more smaller flowcharts. This
is usually done when a flowchart does not fit on a single page, or must be
divided into sections. A connector symbol, which is a small circle with a
letter or number inside it, allows you to connect two flowcharts on the same
page. A connector symbol that looks like a pocket on a shirt, allows you to
connect to a flowchart on a different page.
On-Page Connector
Off-Page Connector
Decision
The diamond is used to represent the true/false statement being tested in a
decision symbol.
Module Call
A program module is represented in a flowchart by rectangle with some
lines to distinguish it from process symbol. Often programmers will make a
distinction between program control and specific task modules as shown
below.
Note: C++ equivalent is the function.
Local module: usually a program control function.
Library module: usually a specific task function.
Flow Lines
Note: The default flow is left to right and top to bottom (the same way you
read English). To save time arrowheads are often only drawn when the flow
lines go contrary the normal.
Examples
We will demonstrate various flowcharting items by showing the flowchart
for some pseudocode.
Functions
Example:
pseudocode: Function with no parameter passing
Function clear monitor
Pass In: nothing
Direct the operating system to clear the monitor
Pass Out: nothing
Endfunction
clear monitor
direct OS to
clear the
monitor
Function clear monitor
Example:
pseudocode: Function main calling the clear monitor function
Function main
Pass In: nothing
Doing some lines of code
Call: clear monitor
Doing some lines of code
Pass Out: value zero to the operating system
Endfunction
do some lines of code
i clear monitor [
do some lines of code
Function main
Sequence Control Structures
The next item is pseudocode for a simple temperature conversion program.
This demonstrates the use of both the on-page and off-page connectors. It
also illustrates the sequence control structure where nothing unusually
happens. Just do one instruction after another in the sequence listed.
Example:
pseudocode: Sequence control structure
Filename: Solution_Lab_04_Pseudocode.txt
Purpose: Convert Temperature from Fahrenheit to
Celsius
Author: Ken Busbee; © 2008 Kenneth Leroy Busbee
Date: Dec 24, 2008
Pseudocode = IPO Outline
input
display a message asking user for the
temperature in Fahrenheit
get the temperature from the keyboard
processing
calculate the Celsius by subtracting 32 from the
Fahrenheit
temperature then multiply the result by 5 then
divide the result by 9. Round up or down to the
whole number.
HINT: Use 32.0 when subtracting to ensure
floating-point accuracy.
output
display the celsius with an appropriate message
pause so the user can see the answer
prompt user
for temp in
Fahrenhiet
gettemp
from
keyboard
Sequence control structure
Step 4
temp plus 0.5
and store in Celsius
Display
message and
Celsius
Sequence control structured
continued
Selection Control Structures
Example:
pseudocode: If then Else
If age > 17
Display a message indicating you can vote.
Else
Display a message indicating you can't vote.
Endif
Display: F T Display:
You can’t age> 17 You can
vote. > ‘ vote.
If then Else control structure
Example:
pseudocode: Case
Case of age
Orfeo: Ghz Display "You can't vote."
18 to 64 Display "Your in your working years."
650 Display "You should be retired."
Endcase
18 to 64
Display:
You should
be retired.
Display:
You’re in
the working
years.
Display:
You can’t
vote.
Case control structure
Iteration (Repetition) Control Structures
Example:
pseudocode: While
count assigned zero
While count < 5
Display "I love computers!"
Increment count
Endwhile
count assigned zero
increment count
Display:
love
computers.
While control structure
Example:
pseudocode: For
For x starts at 0, x < 5, increment x
Display "Are we having fun?"
Endfor
The for loop does not have a standard flowcharting method and you will
find it done in different ways. The for loop as a counting loop can be
flowcharted similar to the while loop as a counting loop.
Display:
Are we
having fun.
For control structure
Example:
pseudocode: Do While
count assigned five
Do
Display “Blast off 1S soon!”
Decrement count
While count > zero
count assigned 5
Display:
Blast off is
soon!
decrement count
Do While control structure
Example:
pseudocode: Repeat Until
count assigned five
Repeat
Display “Blast off 1S soon!”
Decrement count
Until count < one
count assigned 5
Display:
Blast off is
soon!
decrement count
Repeat Until control structure
Definitions
flowcharting
A programming design tool that uses graphical elements to visually
depict the flow of logic within a function.
process symbol
A rectangle used in flowcharting for normal processes such as
assignment.
input/output symbol
A parallelogram used in flowcharting for input/output interactions.
decision symbol
A diamond used in flowcharting for asking a question and making a
decision.
flow lines
Lines (sometimes with arrows) that connect the various flowcharting
symbols.
Practice 10: Introduction to Structured Programming
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Given pseudocode, write the C++ code for a program that uses if then
else and while control structures.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. There are only two categories of control structures.
2. Branching control structures are rarely used in good structured
programming.
3. If then else is a multiway selection control structure.
4. The while control structure is part of the branching category.
5. Pseudocode is better than flowcharting.
Solution:
Answers:
1. false
2. true
3. false
4. false
5. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 10 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_10 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_10 Pseudocode.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file from the Lab_10_Pseudocode.txt file. Name
it: Lab_10.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 10a — Instructions
List the four categories of control structures and provide a brief description
of each category.
If Then Flse
An introduction to the if then else control structure.
Introduction to Two Way Selection
Traditional Two Way Selection
We are going to introduce the control structure from the selection category
that is available in every high level language. It is called the if then else
structure. Asking a question that has a true or false answer controls the if
then else structure. It looks like this:
if the answer to the question is true
then do this
else because it's false
do this
In most languages the question (called a test expression) is a Boolean
expression. The Boolean data type has two values — true and false. Let's
rewrite the structure to consider this:
if expression is true
then do this
else because it's false
do this
Some languages use reserved words of: "if", "then" and "else". Many
eliminate the "then". Additionally the "do this" can be tied to true and false.
You might see it as:
if expression is true
action true
else
action false
And most languages infer the "is true" you might see it as:
if expression
action true
else
action false
The above four forms of the control structure are saying the same thing.
The else word is often not used in our English speaking today. However,
consider the following conversation between a mother and her child.
Child asks, "Mommy, may I go out side and play?"
Mother answers, "If your room is clean then you may go outside and play
or else you may go sit on a chair for five minutes as punishment for asking
me the question when you knew your room was dirty."
Let's note that all of the elements are present to determine the action (or
flow) that the child will be doing. Because the question (your room is clean)
has only two possible answers (true or false) the actions are mutually
exclusive. Either the child 1) goes outside and plays or 2) sits on a chair for
five minutes. One of the actions is executed; never both of the actions.
One Choice — Implied Two Way Selection
Often the programmer will want to do something only if the expression is
true, that is with no false action. The lack of a false action is also referred to
as a "null else" and would be written as:
if expression
action true
else
do nothing
Because the "else do nothing" is implied, it is usually written in short form
like:
if expression
action true
Two Way Selection within C++
The syntax for the if then else control structure within the C++
programming language is:
if (expression)
statement;
else
statement;
Note: The test expression is within the parentheses, but this is not a function
call. The parentheses are part of the control structure. Additionally, there is
no semicolon after the parenthesis following the expression.
Definitions
if then else
A two way selection control structure.
mutually exclusive
Items that do not overlap. Example: true and false.
Boolean Data Type
An introduction to the Boolean data type.
Discussion
The Boolean data type is also known as the logical data type and represents
the concepts of true and false. The name "Boolean" comes from the
mathematician George Boole; who in 1854 published: An Investigation of
the Laws of Thought. Boolean algebra is the area of mathematics that deals
with the logical representation of true and false using the numbers 0 and 1.
The importance of the Boolean data type within programming is that it is
used to control programming structures (if then else, while loops, etc.) that
allow us to implement "choice" into our algorithms.
The Boolean data type has the same attributes and acts or behaves similarly
in all programming languages. The rules within the C++ programming
language are:
C++
Reserved bool
Word
Represent Logical concepts of true and false
Size Usually 1 byte
Nonna! Unsigned
Signage
Domain
(Values O meaning false, and 1 meaning true
Allowed)
C++ syntax true and false are reserved words that can be used as
rule values in expressions
Any value from any data type can be demoted into a
Boolean data type with zero representing false and
all non-zero values representing true.
C++
concept/rule
Most control structures use a test expression that executes either selection
(as in the: if then else) or iteration (as in the while; do while; or for loops)
based on the truthfulness or falseness of the expression. Thus, we often talk
about the Boolean expression that is controlling the structure. Within many
programming languages, this expression must be a Boolean expression and
is governed by a tight set of rules. However, in C++ every data type can be
used as a Boolean expression because the value of any data type within C++
can be demoted into a Boolean value.
Within most languages, expressions that yield Boolean data type values are
divided into two groups. One group uses the relational operators within
their expressions and the other group uses logical operators within their
expressions.
Within the C++ programming language the Boolean data type is one of the
standard or basic data types and is a member of the integer family.
Definitions
Boolean
A data type representing the concepts of true and false.
test expression
An expression used to control programming structures.
Relational Operators
An introduction to the six common relational operators used in
programming.
Overview of the Relational Operators
The relational operators are often used to create a test expression that
controls program flow. This type of expression is also known as a Boolean
expression because they create a Boolean answer or value when evaluated.
There are six common relational operators that give a Boolean value by
comparing (showing the relationship) between two operands. If the
operands are of different data types, implicit promotion occurs to convert
the operands to the same data type.
relational operator
An operator that gives a Boolean value by evaluating the relationship
between two operands.
Operator symbols and/or names vary with different programming
languages. The C++ programming language operators with their meanings
are:
C++ Operator Meaning
< less than
> greater than
<= less than or equal to
>= greater than or equal to
== equality (equal to)
I= inequality (not equal to)
Exercise:
Problem:
Evaluate the following Boolean expressions:
1925
259% 3
3
3]
6
feo i= 13
8
Solution:
Answers:
CONAWMKRWNP
rPoOoOoOrROOrF
. Error, the "not less than" is not a valid operator.
The answers to Boolean expressions within the C++ programming language
are a value of either 1 for true or 0 for false.
Be careful. In math you are familiar with using this symbol = to mean
equal and # to mean not equal. In the C++ programming language the ~ is
not used and the = symbol means assignment.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file. Following the methods of
your compiler/IDE, compile and run the program(s). Study the source code
file(s) in conjunction with other learning materials.
Download from Connexions: Demo Relational Operators.cpp
Compound Statement
An explanation for the need of compound statements within some
programming languages.
The Need for a Compound Statement
For illustration we will use the syntax for the if then else control structure
within the C++ programming language. However this problem generally
exists for all control structures within any language that requires the use of
compound statements. The syntax is:
if (expression)
statement;
else
statement;
Within the C++ programming language there can be only one statement
listed as the action part of a control structure. Often, we will want to do
more than one statement. This problem is overcome by creating a
compound statement. The brace symbols — the opening { and the closing }
- are used to create a compound statement. For example:
if (expression)
{
statement;
statement;
}
else
{
statement;
statement;
i
Because programmers often forget that they can have only one statement
listed as the action part of a control structure; the C++ programming
industry encourages the use of indentation (to see the action parts clearly)
and the use of compound statements (braces), even if there is only one
action. Thus:
if (expression)
statement;
}
else
statement;
}
By writing code in this manner, if the programmer modifies the code by
adding more statements to either the action true or the action false; they will
not introduce either compiler or logic errors. Using indentation and braces
should become standard practice for C++ programmers and programmers in
any other language that require the use of compound statements with the
control structures.
Other Uses of a Compound Statement
"A compound statement is a unit of code consisting of zero or more
statements. It is also known as a block. The compound statement allows a
group of statements to become one single entry. You used a compound
statement in your first program when you formed the body of the function
main. All C++ functions contain a compound statement known as the
function body.
A compound statement consists of an opening brace, optional declarations,
definitions, and statements, followed by a closing brace. Although all three
are optional, one should be present."[ footnote |
Behrouz A. Forouzan and Richard F. Gilberg, Computer Science A
Structured Approach using C++ Second Edition (United States of America:
Thompson — Brooks/Cole, 2004) 100.
Definitions
compound statement
A unit of code consisting of zero or more statements.
block
Another name for a compound statement.
Practice 11: Two Way Selection
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Given pseudocode, write the C++ code for a program that uses the if
then else control structure.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Evaluate the following Boolean expressions:
2D
a
.14>7
.17 <=7
noe
be
sola 7
le 7
CONDMDUBRWN FE
Solution:
Answers:
ONANRWNE
POrROrRRO
. Error, the “not greater than” is not a valid operator.
Miscellaneous Items
Link to: Animated gif showing if then else
Link to: Manipulation of Data Part 2
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 11 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_11 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_11 Pseudocode.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file from the Lab_11_Pseudocode.txt file. Name
it: Lab_11.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 11a — Instructions
Create a table with the six relational operators and their meanings.
Problem 11b — Instructions
Explain why we are using the "if then else" to manipulate the input data in
the example below.
Example:
C++ source code
ip ote olde?)
Nested If Then Else
An explanation of nesting and examples using nested if then else to
demonstrate multiway selection.
Introduction to Mulitway Selection
Nested Control Structures
We are going to first introduce the concept of nested control structures.
Nesting is a concept that places one item inside of another. Consider:
if expression
true action
else
false action
This is the basic form of the if then else control structure. Now consider:
if age is less than 18
you can't vote
if age is less than 16
you can't drive
else
you can drive
else
you can vote
if age is less than 21
you can't drink
else
you can drink
As you can see we simply included as part of the "true action" a statement
and another if then else control structure. We did the same (nested another if
then else) for the "false action". In our example we nested if then else
control structures. Nesting could have an if then else within a while loop.
Thus, the concept of nesting allows the mixing of the different categories of
control structures.
Multiway Selection
One of the drawbacks of two way selection is that we can only consider two
choices. But what do you do if you have more than two choices. Consider
the following which has four choices:
if age equal to 18
you can now vote
else
if age equal to 39
you are middle aged
else
if age equal to 65
you can consider retirement
else
your age iS unimportant
You get an appropriate message depending on the value of age. The last
item is referred to as the default. If the age is not equal to 18, 39 or 65 you
get the default message. In some situations there is no default action.
Consider:
if age equal to 18
you can now vote
else
if age equal to 39
you are middle aged
else
if age equal to 65
you can consider retirement
The last if then else control structure has no "else". It’s implied "else do
nothing". Without the default the multiway selection could be written as a
series of "if then without the else" structures. Consider:
if age equal to 18
you can now vote
if age equal to 39
you are middle aged
if age equal to 65
you can consider retirement
We have shown two ways to accomplish multiway selection. The choice of
using nested if then else control structures or a series of if then control
structures is decided on the existence of a default action (you must use
nested if then else) or programmer preference if there is not a default action
(you may use nested if then else or a series of if then control structures).
if then else Syntax within C++
The syntax for the if then else control structure within the C++
programming language is:
Example:
C++ source code: Layout of an if then else
if (expression)
statement;
i
else
statement;
y
Note:The test expression is within the parentheses, but this is not a
function call. The parentheses are part of the control structure.
Additionally, there is no semicolon after the parenthesis following the
expression.
C++ Example
Multiway selection is often needed to cover all possibilities. Assume that
the user has been prompted for the ages of two people with the answers
stored in variables named age1 and age2. Consider:
Example:
C++ source code
if(age1 > age2)
{
COUE << “\n\nihe first person 1s older.-";
t
else
i
cout << "\n\nThe second person is older.";
i
What if the two persons are the same age? The program incorrectly says the
second person is older. To solve this we must handle all three possibilities.
Consider this mulitway selection example:
Example:
C++ source code
if(age1 == age2)
iL
cout << "\n\nThey are the same age.";
}
else
it
if(age1 > age2)
{
cout << "\n\nThe first person is older.";
}
else
{
cout << "\n\nThe second person is older.";
ls
}
Definitions
nested control structures
Placing one control structure inside of another.
multiway selection
Using control structures to be able to select from more than two
choices.
Logical Operators
An introduction to the three common logical operators used in
programming.
Overview of the Logical Operators
Within most languages, expressions that yield Boolean data type values are
divided into two groups. One group uses the relational operators within
their expressions and the other group uses logical operators within their
expressions.
The logical operators are often used to help create a test expression that
controls program flow. This type of expression is also known as a Boolean
expression because they create a Boolean answer or value when evaluated.
The answers to Boolean expressions within the C++ programming language
are a value of either 1 for true or O for false. There are three common
logical operators that give a Boolean value by manipulating other Boolean
operand(s). Operator symbols and/or names vary with different
programming languages. The C++ programming language operators with
their meanings are:
C++ ,
Operator Meaning Comment Typing
&& Logical two ampersands
and
\ Logical two vertical dashes or
or piping symbols
Logical
nai unary the exclamation point
Note:The vertical dashes or piping symbol is found on the same key as the
backslash \. You use the SHIFT key to get it. It is just above the Enter key
on most keyboards. It may be a solid vertical line on some keyboards and
show as a Solid vertical line on some print fonts.
In most languages there are strict rules for forming proper logical
expressions. An example is:
6 > 4 & 2 <= 14
This expression has two relational operators and one logical operator.
Using the precedence of operator rules the two "relational comparison"
operators will be done before the "logical and" operator. Thus:
1 && 1
or
true && true
The final evaluation of the expression is: 1 meaning true.
We can say this in English as: It is true that six is greater than four and that
two is less than or equal to fourteen.
When forming logical expressions programmers often use parentheses
(even when not technically needed) to make the logic of the expression very
clear. Consider the above complex Boolean expression rewritten:
(6 > 4) && (2 <= 14)
Truth Tables
A common way to show logical relationships is in truth tables.
x y x&&y
false false false
false true false
true false false
true true true
Logical and (&&)
x y X |ly
false false false
false true true
true false true
true true true
Logical or (||)
false true
true false
Logical not (!)
Examples
I call this example of why I hate "and" and love "or".
Everyday as I came home from school on Monday through Thursday; I
would ask my mother, "May I go outside and play?" She would answer, "If
your room is clean and your homework is done then you may go outside
and play." I learned to hate the word "and". I could manage to get one of the
tasks done and have some time to play before dinner, but both of them...
well, I hated "and".
On Friday my mother took a more relaxed view point and when asked if I
could go outside and play she responded, "If your room is clean or your
homework is done then you may go outside and play." I learned to clean my
room quickly on Friday afternoon. Well needless to say, I loved "or".
For the next example, just imagine a teenager talking to their mother.
During the conversation mom says, "After all, your Dad is reasonable!" The
teenager says, "Reasonable. (short pause) Not."
Maybe college professors will think that all their students studied for the
exam. Ha ha! Not. Well, I hope you get the point.
Exercise:
Problem:
Evaluate the following Logical Boolean expressions:
1,25.< 7 || 15> 36
2.15 > 36 [3 <7
3.14>7 &&5<=5
4.4>3 &&17 <=7
5. ! false
6. ! (13 != 7)
7.9!=7 &&!0
8.5 > && 7
Solution:
Answers:
0
1
1
0
1
0
HL
E
ee ee
tror, there needs to be an operand between the operators > and
&&.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file. Following the methods of
your compiler/IDE, compile and run the program(s). Study the source code
file(s) in conjunction with other learning materials.
Definitions
logical operator
An operator used to create complex Boolean expressions.
truth tables
A common way to show logical relationships.
Case Control Structure
An introduction to the case control structure and how it is implemented
using a switch within the C++ programming language.
Traditional Case Control Structure
Multiway Selection using the Case Structure
One of the drawbacks of two way selection is that we can only consider two
choices. But what do you do if you have more than two choices. Consider
the following which has four choices:
if age equal to 18
you can vote
else
if age equal to 39
you're middle aged
else
if age equal to 65
consider retirement
else
age 1S un-important
You get an appropriate message depending on the value of age. The last
item is referred to as the default. If the age is not equal to 18, 39 or 65 you
get the default message. In some situations there is no default action.
Consider this flowchart example:
Display:
You’re
middle
aged.
Display:
Ageis un-
important.
Display:
Consider
retirement.
Display:
You can
vote.
This flowchart is of the case control structure and is used for multiway
selection. The decision box holds the variable age. The logic of the case is
one of equality where in the value in the variable age is compared to the
listed values in order from left to right. Thus, the value stored in age is
compared to 18 or is "age equal to 18". If it is true, the logic flows down
through the action and drops out at the bottom of the case structure. If the
value of the test expression is false, it moves to the next listed value to the
right and makes another comparison. It works exactly the same as our
nested if then else structure.
C++ Code to Accomplish Multiway Selection
Using the same example as above, here is the C++ code to accomplish the
case control structure.
Example:
C++ source code - case structure with integers
Switch (age)
case 18; cout << "\nYoll can vote, ”;
break;
case 39: cout << "\nYou're middle aged.";
break;
case 65: cout << "\nConsider retirement.";
break;
default: cout << "\nAge is un-important.";
}
The first thing you should note is that the C++ programming language does
not formally have a case control structure. It does have a switch control
structure but it acts differently than the traditional case control structure. We
use a break (which is a branching control structure) with the switch to make
it act like the traditional case structure. This is one of the few allowable
ways to use the switch with break within the C++ programming language to
simulate the traditional case structure. All other uses of the switch or break
are to be avoided if you are to stay within the bounds of good structured
programming techniques.
The value in the variable age is compared to the first "case" (note: case is
one of the C++ reserved words) which is the value 18 (also called the listed
value) using an equality comparison or is "age equal to 18". If it is true, the
cout is executed which displays “You can vote.” and the next line of code
(the break) is done (which jumps us to the end of the control structure). If it
is false, it moves on to the next case for comparison.
Most programming languages, including C++, require the listed values for
the case control structure be of the integer family of data types. This
basically means either an integer or character data type. Consider this
example that uses character data type (choice is a character variable):
Example:
C++ source code - case structure with characters
Switch (choice)
x
case 'A':
case 'B':
case 'C':
default:
harder.";
}
COut <<
break;
COuUE <<
break;
COUEL <<
break;
GOQUE=<—
"\nYou are an A student.";
"\nYou are a B student.";
"\nYou are a C student.";
"\nMaybe you should study
Limitations of the Case Control Structure
Most programming languages, including C++, do not allow ranges of
values for case like structures. Consider this flowcharting example that used
ranges:
18 to 64
. Display: ‘
Display: aoe Display:
You can’t tern You should
vote. 8 be retired.
years.
Consider also the following pseudocode for the same logic:
Case of age
OO. a7, Display “You can = vote:
18 to 64 Display "You’re in your working
years."
65.4 Display "You should be retired."
Endcase
Using the case control structure when using non integer family or ranges of
values is allowed when designing a program and documenting that design
with pseudocode or flowcharting. However, the implementation in most
languages would follow a nested if then else approach with complex
Boolean expressions. The logic of the above examples would look like this:
if age > 0 and age <= to 17
display You can’t vote.
else
if age is >= 18 and age <= 64
display You’re in your working years.
else
display You should be retired.
Good Structured Programming Methods
Most text book authors confirm that good structured programming
techniques and habits are more important than concentrating on the
technical possibilities and capabilities of the language that you are using to
learn programming skills. Remember, this module is concentrating on
programming fundamentals and concepts and it uses the C++ programming
language to build our initial programming skills. It is not a created with the
intent to cover the C++ programming language in detail, despite the fact
that at times we have to cover C++ language mechanics.
Definitions
case
A control structure that does mulitway selection.
switch
A C++ control structure that can be made to act like a case control
structure.
Branching Control Structures
An introduction to the common types of branching control structures and
which ones are allowed in good structured programming.
Discussion
The branching control structures allow the flow of execution to jump to a
different part of the program. The common branching control structures that
are used with other control structures are: break, continue and goto. These
are rarely used in modular structured programming with one exception.
That exception is in relation to creating the case within the selection
category of control structures. Within C++ the break is used with the switch
to create a structure that acts like the traditional case structure. There is one
other branching control structure that is often not viewed as branching
control structure. It is: return; which is used with functions. Thus, there are
two commonly used branching control reserved words used in C++; break
and return. Additionally, we will add to our list of branching items a pre-
defined function commonly used in the C++ programming language of:
exit; that is part of the C standard library (cstdlib). Some definitions:
Definitions
branching control structures
Allow the flow of execution to jump to a different part of the program.
break
A branching control structure that terminates the existing structure.
continue
A branching control structure that causes a loop to stop its current
iteration and begin the next one.
goto
A branching control structure that causes the logic to jump to a
different place in the program.
retum
A branching control structure that causes a function to jump back to
the function that called it.
exit
A pre-defined function used to prematurely stop a program and jump
to the operating system.
We will discuss each item indicating which ones are allowed or not allowed
within good structured programming practices.
Examples
break
The break is used in one of two ways; with the switch (a C++ programming
structure) to make it act like a case structure (it's more common name
within most programming languages) or as part of a looping process to
break out of the loop. The first usage is allowed in good structured
programming and the second is not allowed in good structured
programming.
Example:
C++ source code
Switch (age)
case 18% cout << "\nYou Can vote.”;
break;
case 39: cout << "\nYou are middle aged.";
break;
case 65: cout << "\nYou are at retirement age.";
break;
default: cout << "\nYour current age is not
important.";
i
The following is an unauthorized use of break in a loop and it gives the
appearance that the loop will execute 8 times, but the break statement
causes it to stop during the fifth iteration.
Example:
C++ source code
counter = 0;
while(counter < 8)
i
cout << counter << endl;
if (counter == 4)
{
break;
i
counter++;
i
continue
The continue structure is not allowed in good structured programming. The
following gives the appearance that the loop will print to the monitor 8
times, but the continue statement causes it not to print number 4.
Example:
C++ source code
for(counter = 0; counter < 8; counter++)
{
if (counter == 4)
it
continue;
J
cout << counter << endl;
}
goto
The goto structure is not allowed in good structured programming. It is with
a certain amount of hesitancy that we even show it. Many textbooks do not
cover the goto. Within the C++ programming language you create a label
with an identifier name followed by a colon. You use the command word
goto followed by the label. A label can be used before it is declared.
Example:
C++ source code
some lines of code;
goto mynewspot; //jumps to the
label
some lines of code;
some lines of code;
some lines of code;
mynewspot: some statement; //Declared label
some lines of code;
return
The return is allowed in good structured programming, but only at the end
of a function. A function should not pre-maturely end by having the logic of
the function have it terminate by jumping back to the function that called it.
Example:
C++ source code
J Te ae ay I Dees Te eee Tee eg ee eae se re a
Kn ee
// get data
of
KKEKKKK
void get_data(void)
1
// Input = Test Data = 5678.9, 5432.1
cout << "\nEnter the length of the property in
feet --->: ";
cin >> property_length;
cout << "\nEnter the width of the property in
feet ---->: ";
cin >> property_width;
return;
i
exit
Although exit is technically a pre-defined function, it is covered here
because of its common usage in programming. A good example is the
opening a file and then testing to see if the file was actually opened. If not,
we have an error that usually indicates that we want to pre-maturely stop
the execution of the program. Within the C++ programming language the
exit function terminates the running of the program and in the process
returns an integer value back to the operating system. It fits the definition of
branching which is to jump to some other place in the program. In our
example the value returned to the operating system is the value of the
constant named: EXIT_FAILURE.
Example:
C++ source code
inData.open(filename); //Open input file
if (/inData) //Test to see if file was
opened
{
cout << "\n\nError opening file: " << filename
<< Wid abe
pause(); //Pause - user reads
message
exit (EXIT_FAILURE); //Allows a pre-mature jump
to OS
y
Practice 12: Multiway Selection
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Identify which selection control structures are two-way selection and
which are multiway selection.
3. Understand, define and/or explain case, switch and nested if then else.
4. Be able to write pseudo code or flowcharting for the case control
structure.
5. Be able to write C++ source code for a case structure using equality
and listed values (switch with break to act like a case structure).
6. Be able to write C++ source code for a case structure using ranges of
values or floating-point values (nested if then else to act like a case
structure).
7. When feasible, be able to convert C++ source code from switch acting
like a case to nested if then else and vice versa.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Evaluate the following Logical Boolean expressions:
1.25 > 39 || 15 > 36
2.19 > 26 || 13<17
3.14<7 && 6 <=6
AAS Re d7 S=7
Os | true
6. ! (13 == 7)
7.9!=7 &&!1
8.6 < && 8
Solution:
Answers:
1.0
Z.%
3.0
4.1
oa. 0)
6.1
7.0
8. Error, there needs to be an operand between the operators < and
&&.
Miscellaneous Items
Link to: Manipulation of Data Part 3
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 12 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
Chapter_12 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_12a.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
Compile and run the Lab_12a.cpp source code file. Understand how it
works.
Copy the source code file Lab_12a.cpp naming it: Lab_12b.cpp
Convert the nested if then else to a switch with breaks.
Build (compile and run) your program.
After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 12a — Instructions
Flowchart the following pseudocode:
Example:
pseudocode
Case of shoe_size
4 to 6 sDisplay™ Small.
7 to 9 Display "Medium."
a0) “ae Display "Large."
Endcase
Problem 12b — Instructions
The "Flip-Flops" is a unique shoe store that only sells flip-flops. Adult shoe
sizes less than 4 are handled in the children’s department, thus we don’t
need to concern ourselves with sizes less than 4. Half shoe sizes are to be
rounded down, thus the prompt to the user that happens before this case
structure will have addressed that issue. The variable shoe_size will be an
integer value between 4 and 1,000,000,000 (one billion).
Write C++ source code for the following pseudocode:
Example:
pseudocode
Case of shoe_size
4to 6 (Display = Small.
7 to 9 Display "Medium."
10+ Display "Large."
Endcase
Problem 12c — Instructions
Write C++ source code for the following pseudocode:
Example:
pseudocode
If age equal to 24
Display a message "You’re the same age as
Melinda. "
Else
If age equal to 27
Display a message "You’re the same age as
RUE
Else
If age equal to 34
Display a message "You’re the same age as
Ben."
Else
Display a message "You’re age is un-
LMPOr tallies...
Endit
Endit
Endif
Do While Loop
An introduction to the do while control structure with examples in the C++
programming language.
Introduction to Test After Loops
There are two commonly used test after loops in the iteration (or repetition)
category of control structures. They are: do while and repeat until. This
module covers the: do while.
Understanding Iteration in General — do while
The concept of iteration is connected to possibly wanting to repeat an
action. Like all control structures we ask a question to control the execution
of the loop. The term loop comes from the circular looping motion that
occurs when using flowcharting. The basic form of the do while loop is as
follows:
do
some statements or action
some statements or action
some statements or action
update the flag
while the answer to the question is true
In every language that I know the question (called a test expression) is a
Boolean expression. The Boolean data type has two values — true and false.
Let's rewrite the structure to consider this:
do
some statements or action
some statements or action
some statements or action
update the flag
while expression is true
Within the do while control structure there are three attributes of a properly
working loop. They are:
e Action or actions
e Update of the flag
e Test expression
The English phrasing is, "You do the action while the expression is true".
This is looping on the true. When the test expression is false, you stop the
loop and go on with the next item in the program. Notice, because this is a
test after loop the action will always happen at least once. It is called a test
after loop because the test comes after the action. It is also sometimes
called a post-test loop, meaning the test is post (or Latin for after) the action
and update.
The do while Structure within C++
Syntax
The syntax for the do while control structure within the C++ programming
language is:
do
statement;
statement;
statement;
statement; // This statement updates the
flag;
while (expression);
Note:The test expression is within the parentheses, but this is not a
function call. The parentheses are part of the control structure.
Additionally, there is a semicolon after the parenthesis following the
expression.
An Example
Example:
C++ source code: do while loop
do
it
cout << "\nWhat 1s your age? ";
cin >> age_user;
cout << "\nWhat 1s your friend's age? ";
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
COuE <= “\nDo you want LO GO It again? y or ni”;
cin >> loop_response;
while (loop_response == 'y');
The three attributes of a test after loop are present. The action part consists
of the 6 lines that prompt for data and then displays the total of the two
ages. The update of the flag is the displaying the question and getting the
answer for the variable loop_response. The test is the equality relational
comparison of the value in the flag variable to the lower case character of y.
This type of loop control is called an event controlled loop. The flag
updating is an event where someone decides if they want the loop to
execute again.
Using indentation with the alignment of the loop actions and flag update is
normal industry practice within the C++ community.
Infinite Loops
At this point it's worth mentioning that good programming always provides
for a method to insure that the loop question will eventually be false so that
the loop will stop executing and the program continues with the next line of
code. However, if this does not happen then the program is in an infinite
loop. Infinite loops are a bad thing. Consider the following code:
Example:
C++ source code: infinite loop
loop_response = '‘y';
do
1
cout << "\nWhat 1s your age? ";
Cin >> age_user;
cout << "\nWhat is your friend's age? ";
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
while (loop_response == 'y');
The programmer assigned a value to the flag before the loop and forgot to
update the flag. Every time the test expression is asked it will always be
true. Thus, an infinite loop because the programmer did not provide a way
to exit the loop (he forgot to update the flag).
Consider the following code:
Example:
C++ source code: infinite loop
do
{
cout << "\nWhat 1s your age? ";
cin >> age_user;
cout << "\nWhat 1s your friend's age? ";
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
cout << "\nDo you want to do it again? y orn";
cin >> loop_response;
while (loop_response = 'y');
No matter what the user replies during the flag update, the test expression
does not do a relational comparison but does an assignment. It assigns 'y' to
the variable and asks if 'y' is true? Since all non-zero values are treated as
representing true within the Boolean concepts of the C++ programming
language, the answer to the text question is true. Viola, you have an infinite
loop.
Definitions
do while
A test after iteration control structure available in C++.
action item
An attribute of iteration control structures.
update item
An attribute of iteration control structures.
test item
An attribute of iteration control structures.
at least once
Indicating that test after loops execute the action at least once.
infinite loop
No method of exit, thus a bad thing.
Flag Concept
An explanation of how the flag concept is used within computer
programming.
Concept Discussion
For centuries flags have been used as a signal to let others know something
about the group or individual that is displaying, flying or waving the flag.
There are country flags and state flags. Ships at sea flew the flag of their
country. Pirates flew the skull and cross bones. A yellow flag was used for
quarantine, usually the plague. Even pirates stayed away. Today, some
people might recognize the flag used by scuba divers. The Presidents of
most countries have a flag. At a race car event they use the checkered flag
to indicate the race is over.
NE
FD SSS
Various Flags
Computer programming uses the concept of a flag in the same way that
physical flags are used. A flag is anything that signals some information to
the person looking at it.
Computer Implementation
Any variable or constant that holds data can be used as a flag. You can think
of the storage location as a flag pole. The value stored within the variable
conveys some meaning and you can think of it as being the flag. An
example might be a variable named: gender which is of the character data
type. The two values normally stored in the variable are: 'F' and 'M'
meaning female and male. Then, somewhere within a program we might
look at the variable to make a decision:
Example:
flag controling an if then control structure
if gender equals 'F'
display "Are you pregnant?"
get answer from user store in pregnant variable
Looking at the flag implies comparing the value in the variable to another
value (a constant or the value in another variable) using a relational
operator (in our above example: equality).
Control structures are "controlled" by using a test expression which is
usually a Boolean expression. Thus, the flag concept of "looking" at the
value in the variable and comparing it to another value is fundamental to
understanding how all control structures work.
Two Flags with the Same Meaning
Sometimes we will use an iteration control structure of do while to allow us
to decide if we want to do the loop action again. A variable might be named
"loop_response" with the user prompted for their answer of 'y' for yes or 'n'
for no. Once the answer is retrieved from the keyboard and stored in our
flag variable of "loop_response" the test expression to control the loop
might be:
Example:
simple flag comparison
Joop response equals y~
This is fine but what if the user accidentally has on the caps lock. Then his
response of "Y' would not have the control structure loop and perform the
action again. The solution lies in looking at the flag twice. Consider:
Example:
complex flag comparison
loop_response equals 'y' or loop_response equals
ry!
We look to see if the flag is either a lower case y or an upper case Y by
using a more complex Boolean expression with both relational and logical
operators.
Multiple Flags in One Byte
Within assembly language programming and in many technical programs
that control special devices; the use of a single byte to represent several
flags is common. This is accomplished by having each one of the 8 bits that
make up the byte represent a flag. Each bit has a value of either 1 or 0 and
can represent true and false, on or off, yes or no, etc.
Definitions
flag
A variable or constant used to store information that will normally be
used to control the program.
Assignment vs Equality within C++
An explanation with examples of a common mistake made by accidently
confusing the assignment operator with the equality operator within the
C++ programming language.
General Discussion
Most control structures use a test expression that executes either selection
(as in the: if then else) or iteration (as in the while; do while; or for loops)
based on the truthfulness or falseness of the expression. Thus, we often talk
about the Boolean expression that is controlling the structure. Within many
programming languages, this expression must be a Boolean expression and
is governed by a tight set of rules. However, in C++ every data type can be
used as a Boolean expression, because every data type can be demoted into
a Boolean value by using the rule/concept that zero represents false and all
non-zero values represent true.
Within C++ we have the potential added confusion of the equals symbol as
an operator that does not represent the normal math meaning of equality
that we have used for most of our life. The equals symbol with C++ means:
assignment. To get the equality concept of math within C++ we use two
equal symbols to represent the relational operator of equality. Let's
consider:
if (pig = 'y')
{
cout << "\nPigs are good";
}
else
:
cout << "\nPigs are bad.";
}
The test expression of the control structure will always be true, because the
expression is an assignment (not the relational operator of ==). It assigns
the 'y' to the variable pig, then looks at the value in pig and determines that
it is not zero; therefore the expression is true. And it will always be true and
the else part will never be executed. This is not what the programmer had
intended. Let's consider:
do
iL
cout << "\nPigs are good";
cout << "\nDo it again, answer y orn: ";
Cli] dom ttsagain
while dolttlagain =— vy)
The loop's test expression will always be true, because the expression is an
assignment (not the relational operator of ==). It assigns the 'y' to the
variable do_it_again, then looks at the value in do_it_again and determines
that it is not zero; therefore the expression is true. And it will always be true
and you have just created an infinite loop. As a reminder, infinite loops are
not a good thing.
These examples are to remind you that you must be careful in creating your
test expressions so that they are indeed a question usually involving the
relational operators.
Don't get caught using assignment for equality.
Repeat Until Loop
An introduction to the repeat until control structure.
Introduction to Test After Loops
There are two commonly used test after loops in the iteration (or repetition)
category of control structures. They are: do while and repeat until. This
module covers the: repeat until.
Understanding Iteration in General — repeat until
The concept of iteration is connected to possibly wanting to repeat an
action. Like all control structures we ask a question to control the execution
of the loop. The term loop comes from the circular looping motion that
occurs when using flowcharting. The basic form of the repeat until loop is
as follows:
repeat
some statements or action
some statements or action
some statements or action
update the flag
until the answer to the question becomes true
In every language that I know the question (called a test expression) is a
Boolean expression. The Boolean data type has two values — true and false.
Let's rewrite the structure to consider this:
repeat
some statements or action
some statements or action
some statements or action
update the flag
until expression becomes true
Within the repeat until control structure there are three attributes of a
properly working loop. They are:
e Action or actions
e Update of the flag
e Test expression
The English phrasing is, "You repeat the action until the expression
becomes true". This is looping on the false. When the test expression
becomes true, you stop the loop and go on with the next item in the
program. Notice, because this is a test after loop the action will always
happen at least once. It is called a "test after loop" because the test comes
after the action. It is also sometimes called a post-test loop, meaning the test
is post (or Latin for after) the action and update.
The repeat until Structure within C++
Well, it just does not exist. Most programming languages have either the do
while or the repeat until control structures, but not both.
Definitions
repeat until
A test after iteration control structure that is not available in C++.
Practice 13: Test After Loops
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Identify which selection control structures are test after iteration.
3. Be able to write pseudo code or flowcharting for the do while control
structure.
4. Be able to write C++ source code for a do while control structure.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. The do while and repeat until structure act exactly the same.
2. Students sometimes confuse assignment and equality.
3. The repeat until looping control structure is available in all
programming languages.
4. Because flags are often used, they are usually a special data type.
5. The do while is a test before loop.
Solution:
Answers:
1. false
2. true
3. false
4. false
5. false
Miscellaneous Items
Link to: Animated gif showing a do while loop
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 13 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_13 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab 13 Pseudocode.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file from the Lab_13_Pseudocode.txt file. Name
it: Lab_13.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 13a — Instructions
Flowchart the following pseudocode:
Example:
pseudocode
Do
Display "I like cheese cake!"
Display "Do it again? y or n ---> "
Get answer from keyboard
While answer is '‘y'
Increment and Decrement Operators
An introduction to the increment and decrement operators used in
programming with details of C++ usage.
General Discussion
The idea of increment or decrement is to either add or subtract 1 from a
variable that is usually acting as a flag. Using a variable named counter; in
generic terms, for example:
increment the counter
The concept is:
counter is assigned counter + 1
That is you fetch the existing value of the counter and add one then store
the answer back into the variable counter. Many programming languages
allow their increment and decrement operators to only be used with the
integer data type. Programmers will sometimes use inc and dec as
abbreviations for increment and decrement respectively.
Operator symbols and/or names vary with different programming
languages. The C++ programming language operators with their meanings
are:
C++ Operator Meaning
bee increment, two plus signs
-- decrement, two minus signs
C++ Code Examples
Basic Concept
Within the C++ programming language the increment and decrement are
often used in this simple generic way. The operator of increment is
represented by two plus signs in a row. Examples:
counter = counter + 1;
counter += 1;
countert+t;
++counter;
As C++ statements, the four examples all do the same thing. They add 1 to
the value of whatever is stored in counter. The decrement opereator is
represented by two minus signs in a row. They would subtract 1 from the
value of whatever was in the variable being decremented. The precedence
of increment and decrement depends on if the operator is attached to the
right of the operand (postfix) or to the left of the operand (prefix). Within
C++ postfix and prefix do not have the same precedence.
Postfix Increment
Postfix increment says to use my existing value then when you are done
with the other operators; increment me. An example:
int oldest = 44; // variable set up with
Iimitialazation
then later on in the code
age = oldest++;
The first use of the oldest variable is an Rvalue context where the existing
value of 44 is pulled or fetched and then assigned to the variable age; then
the variable oldest is incremented with its value changing from 44 to 45.
This seems to be a violation of precedence because increment is higher
precedence than assignment. But that is how postfix increment works
within the C++ programming language.
Prefix Increment
Prefix increment says to increment me now and use my new value in any
calculation. An example:
int oldest = 44; // variable set up with
Initialization
then later on in the code
age = ++oldest;
The variable oldest is incremented with the new value changing it from 44
to 45; then the new value is assigned to age.
In postfix age is assigned 44 in prefix age is assigned 45. One way to help
remember the difference is to think of postfix as being polite (use my
existing value and return to increment me after the other operators are done)
where as prefix has an ego (I am important so increment me first and use
my new value for the rest of the evaluations).
Allowable Data Types
Within some programming languages, increment and decrement can be
used only on the integer data type. C++ however, expands this not only to
all of the integer family but also to the floating-point family (float and
double). Incrementing 3.87 will change the value to 4.87. Decrementing 'C'
will change the value to 'B'. Remember the ASCII character values are
really one byte unsigned integers (domain from 0 to 255).
Exercises
Exercise:
Problem:
Evaluate the following items using increment or decrement:
1. True or false: x = x +1 and x+=1 and x++ all accomplish
increment?
2. Given: int y = 19; and int z; what values will y and z have after: z
=e
3. Given: double x = 7.77; and int y; what values will x and y have
after: y = ++x;
4. Is this ok? Why or why not? 6 * ++(age -3)
Solution:
Answers:
1. true
2. y is: 18 and z is: 19
3. x is: 8.77 and y is: 8 Note: truncation of 8.77 to 8 upon demotion.
4. Not ok. Error, the item incremented must have Lvalue attributes,
usually a variable. It is an expression not a variable.
Definitions
increment
Adding one to the value of a variable.
decrement
Subtracting one from the value of a variable.
postfix
Placing the increment or decrement operator to the right of the
operand.
prefix
Placing the increment or decrement operator to the left of the operand.
While Loop
An introduction to the while control structure with examples in the C++
programming language.
Introduction to Test Before Loops
There are two commonly used test before loops in the iteration (or
repetition) category of control structures. They are: while and for. This
module covers the: while.
Understanding Iteration in General — while
The concept of iteration is connected to possibly wanting to repeat an
action. Like all control structures we ask a question to control the execution
of the loop. The term loop comes from the circular looping motion that
occurs when using flowcharting. The basic form of the while loop is as
follows:
initlablizattvon of the flag
while the answer to the question is true then do
some statements or action
some statements or action
some statements or action
update the flag
In almost all languages the question (called a test expression) is a Boolean
expression. The Boolean data type has two values — true and false. Let's
rewrite the structure to consider this:
initialization of the flag
while the expression is true then do
some statements or action
some statements or action
some statements or action
update the flag
Within the while control structure there are four attributes to a properly
working loop. They are:
¢ Initializing the flag
e Test expression
e Action or actions
¢ Update of the flag
The initialization of the flag is not technically part of the control structure,
but a necessary item to occur before the loop is started. The English
phrasing is, "While the expression is true, do the following actions". This is
looping on the true. When the test expression is false, you stop the loop and
go on with the next item in the program. Notice, because this is a test before
loop the action might not happen. It is called a test before loop because
the test comes before the action. It is also sometimes called a pre-test loop,
meaning the test is pre (or Latin for before) the action and update.
Human Example of the while Loop
Consider the following one-way conversation from a mother to her child.
Child: The child says nothing, but mother knows the child had Cheerios for
breakfast and history tells us that the child most likely spilled some
Cheerios on the floor.
Mother says: "While it is true that you see (As long as you can see) a
Cheerio on floor, pick it up and put it in the garbage."
Note: All of the elements are present to determine the action (or flow) that
the child will be doing (in this case repeating). Because the question (can
you see a Cheerios) has only two possible answers (true or false) the action
will continue while there are Cheerios on the floor. Either the child 1) never
picks up a Cheerio because they never spilled any or 2) picks up a Cheerio
and keeps picking up Cheerios one at a time while he can see a Cheerio on
the floor (that is until they are all picked up).
The while Structure within C++
Syntax
The syntax for the while control structure within the C++ programming
language is:
statement; // This statement initializes
the flag;
while (expression)
iL
statement;
statement;
statement;
statement; // This statement updates the
filag,
}
Note:The test expression is within the parentheses, but this is not a
function call. The parentheses are part of the control structure.
Additionally, there is not a semicolon after the parenthesis following the
expression.
An Example
Example:
C++ source code: while
loop_response = 'y';
while (loop_response == '‘'y')
{
cout << "\nWhat is your age? ";
cin >> age_user;
cout << "\nWhat is your friend's age? ";
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
couL <= "“\nDo yourwant tosd® 1t again? y or 1
cin >> loop_response;
i
The four attributes of a test before loop are present. The initialization of the
flag. The test is the equality relational comparison of the value in the flag
variable to the lower case character of y. The action part consists of the 6
lines that prompt for data and then displays the total of the two ages. The
update of the flag is the displaying the question and getting the answer for
the variable loop_response.
This type of loop control is called an event controlled loop. The flag
updating is an event where someone decides if they want the loop to
execute again.
Using indentation with the alignment of the loop actions and flag update is
normal industry practice within the C++ community.
Infinite Loops
At this point it's worth mentioning that good programming always provides
for a method to insure that the loop question will eventually be false so that
the loop will stop executing and the program continues with the next line of
code. However, if this does not happen then the program is in an infinite
loop. Infinite loops are a bad thing. Consider the following code:
Example:
C++ source code: infinite loop
loop_response = 'y';
while (loop_response == 'y')
iL
cout << "\nWhat 1s your age? ";
cin >> age_user;
cout << "\nwWhat is your friend's age? ";
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
y
The programmer assigned a value to the flag before the loop which is
correct. However, he forgot to update the flag. Every time the test
expression is asked it will always be true. Thus, an infinite loop because the
programmer did not provide a way to exit the loop (he forgot to update the
flag). Consider the following code:
Example:
C++ source code: infinite loop
loop_response = 'y';
while (loop_response = 'y')
{
cout << "\nWhat is your age? ";
cin >> age_user;
cout << "\nWhat is your friend's age? ";
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
COuE <= “\nDo you want LO ao It again? y or ni”;
cin >> loop_response;
i
No matter what the user replies during the flag update, the test expression
does not do a relational comparison but does an assignment. It assigns 'y' to
the variable and asks if 'y' is true? Since all non-zero values are treated as
representing true within the Boolean concepts of the C++ programming
language, the answer to the test expression is true. Viola, you have an
infinite loop.
Example:
C++ source code: infinite loop
loop_response = 'y';
while (loop_response == 'y');
COUL <= \nWhal as your age? 7;
cin >> age_user;
COUE << ~\nWhat 1s your Triend s. age? ~;
cin >> age_friend;
cout >> "\nTogether your ages add up to: ";
cout >> (age_user + age_friend);
CcOuE <= »\nDo you want To do At again? y or ni’;
Cin >> loop_response;
i
The undesirable semi-colon on the end of while line causes the action of the
while loop to be the "nothingness" between the closing parenthesis and the
semi-colon. The program will infinitely loop because there is no action (that
is no action and no update). If this is the first item in your program it will
appear to start but there will be no output.
Counting Loops
The examples above are for an event controlled loop. The flag updating is
an event where someone decides if they want the loop to execute again.
Often the initialization sets the flag so that the loop will execute at least
once.
Another common usage of the while loop is as a counting loop. Consider:
Example:
C++ source code: while loop that is counting
counter = Q;
while (counter < 5)
iL
cout << "\nI love ice cream!";
counter++;
}
The variable counter is said to be controlling the loop. It is set to zero
(called initialization) before entering the while loop structure and as long as
it is less than 5 (five); the loop action will be executed. But part of the loop
action uses the increment operator to increase counter's value by one. After
executing the loop five times (once for counter's values of: 0, 1, 2, 3 and 4)
the expression will be false and the next line of code in the program will
execute. A counting loop is designed to execute the action (which could be
more than one statement) a set of given number of times. In our example,
the message is displayed five times on the monitor. It is accomplished my
making sure all four attributes of the while control structure are present and
working properly. The attributes are:
e Initializing the flag
e Test expression
e Action or actions
Update of the flag
Missing an attribute might cause an infinite loop or give undesired results
(does not work properly).
Infinite Loops
Consider:
Example:
C++ source code: infinite loop
counter = 0;
while (counter < 5)
i
cout << "\nI love ice cream!";
i
Missing the flag update usually causes an infinite loop.
Variations on Counting
In the following example, the integer variable age is said to be controlling
the loop (that is the flag). We can assume that age has a value provided
earlier in the program. Because the while structure is a test before loop; it is
possible that the person’s age is 0 (zero) and the first time we test the
expression it will be false and the action part of the loop would never be
executed.
Example:
C++ source code: while as a counting loop
while (0 < age)
cout << "\nI love candy!";
age--;
j
Consider the following variation assuming that age and counter are both
integer data type and that age has a value:
Example:
C++ source code: while as a counting loop
counter = 0;
while (counter < age)
{
cout << “\nl Love corn chips!”;
counter++;
i
This loop is a counting loop similar to our first counting loop example. The
only difference is instead of using a literal constant (in other words 5) in our
expression, we used the variable age (and thus the value stored in age) to
determine how many times to execute the loop. However, unlike our first
counting loop example which will always execute exactly 5 times; it is
possible that the person’s age is 0 (zero) and the first time we test the
expression it will be false and the action part of the loop would never be
executed.
Definitions
while
A test before iteration control structure available in C++.
loop attributes
Items associated with iteration or looping control structures.
initialize item
An attribute of iteration control structures.
might not happen
Indicating that test before loops might not execute the action.
event controlled
Using user input to control a loop.
counting controlled
Using a variable to count up or down to control a loop.
Practice 14: Test Before Loops
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Identify which selection control structures are test before iteration.
3. Be able to write pseudo code or flowcharting for the while control
structure.
4. Be able to write C++ source code for the while control structure.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Evaluate the following items using increment or decrement:
1. True or false: X = X - 1; andxX -= 1} and
all accomplish decrement.
2.Given:int y = 26; andint Z; what values will y and z
have after: Z = y++;
3. Given: double x = 4.44; andint y; what values will x
and y have after:
ass
4. As an expression: 10 / ++(money * 4) Is this ok? Why or
why not?
Solution:
Answers:
1. true
2.y is: 27 and z is: 26
3. x is: 3.44 and y is: 3 Note: truncation of 3.44 to 3 upon demotion
to integer data type.
4. Not ok. Error, the item incremented must have Lvalue attributes,
usually a variable. Because of the parentheses, it is an expression
not a variable.
Miscellaneous Items
Link to: Animated gif showing a while loop
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 14 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_14 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab 14 Pseudocode.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file from the Lab_14_ Pseudocode.txt file. Name
it: Lab_14.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 14a — Instructions
Flowchart the following pseudocode:
Example:
For Loop
An introduction to the for control structure with examples in the C++
programming language.
Introduction to Test Before Loops
There are two commonly used test before loops in the iteration (or
repetition) category of control structures. They are: while and for. This
module covers the: for.
Understanding Iteration in General — for
In most programming languages the for loop is used exclusively for
counting; that is to repeat a loop action as it either counts up or counts
down. There is a starting value and a stopping value. The question that
controls the loop is a test expression that compares the starting value to the
stopping value. This expression is a Boolean expression and is usually
using the relational operators of either less than (for counting up) or greater
than (for counting down). The term loop comes from the circular looping
motion that occurs when using flowcharting. The basic form of the for loop
(counting up) is as follows:
fOr
initialization of the starting value
starting value is less than the stopping value
some statements or action
some statements or action
some statements or action
increment the starting value
It might be best to understand the for loop by understanding a while loop
acting like a counting loop. Let's consider;
initialization of the starting value
while the starting value is less than the stopping
value
some statements or action
some statements or action
some statements or action
increment the starting value
Within the for control structure there are four attributes to a properly
working loop. They are:
¢ Initializing the flag — done once
e Test expression
e Action or actions
e Update of the flag
The initialization of the flag is not technically part of the while control
structure, but it is usually part of the for control structure. The English
phrasing is, "For x is 1; x less than 3; do the following actions; increment x;
loop back to the test expression". This is doing the action on the true. When
the test expression is false, you stop the loop and go on with the next item
in the program. Notice, because this is a test before loop the action might
not happen. It is called a test before loop because the test comes before
the action. It is also sometimes called a pre-test loop, meaning the test is pre
(or Latin for before) the action and update.
The for Structure within C++
Syntax
The syntax of the for loop control structure within the C++ programming
language is:
for (initializations; expression; updates)
{
statement;
statement;
statement;
}
Note:The initializations, test expression and updates are within the
parentheses (each separated by a semi-colon), but this is not a function call.
The parentheses are part of the control structure. Additionally, there is not
a semicolon after the parenthesis following the expression.
An Example
Example:
C++ source code: for
for (counter = 0; counter < 5; counter++)
{
cout << "\nI love ice cream!";
}
The four attributes of a test before loop (remember the for loop is one
example of a test before loop) are present.
¢ The initialization of the flag to a value of 0.
e The test is the less than relational comparison of the value in the flag
variable to the constant value of 5.
e The action part consists of the 1 line of output.
¢ The update of the flag is done with the increment operator.
Using indentation with the alignment of the loop actions is normal industry
practice within the C++ community.
Infinite Loops
At this point it's worth mentioning that good programming always provides
for a method to insure that the loop question will eventually be false so that
the loop will stop executing and the program continues with the next line of
code. However, if this does not happen then the program is in an infinite
loop. Infinite loops are a bad thing. Consider the following code:
Example:
C++ source code: infinite loop
for (counter = 0; counter < 5;)
{
cout << "\nI love ice cream!";
i
The programmer assigned a value to the flag during the initialization step
which is correct. However, he forgot to update the flag (the update step is
missing). Every time the test expression is asked it will always be true.
Thus, an infinite loop because the programmer did not provide a way to exit
the loop (he forgot to update the flag).
Multiple Items in the Initialization and Update
The following shows the use of the sequence operator to separate the
multiple initializations and multiple updates. This is not available in most
languages, thus is more unique to the C++ programming language.
Example:
C++ source code: for with multiple initializations and updates
for (x = 0, y = 10; x < 10; x++, y--)
{
cout << x * y << endl;
i
Counting Loop Conversion — a while into a for
Below is a color coded the conversion of a while loop that displays a
message exactly three times (which is a counting loop) into a for loop using
C++ programming language syntax. The four loop attributes are color
highlighted as follows:
blue is the initialize
orange is the test
green is the action
red is the update
counter=0;
while (counter < 3)
{
cout << "\nPlease be careful driving in Houston.";
counter++;
}
for (counter = 0; counter < 3; counter++)
{
cout << "\ nPlease be careful driving in Houston.";
}
Miscellaneous Information about the for Structure
Many languages (Pascal, FORTRAN, and other) have a for loop structure
that is used exclusively for counting. The for loop in the C++ programming
language is much more versatile and can be used (and generally is used) in
place of the while loop structure. In reality a counting loop is just a
particular use of a while loop.
The name for comes from mathematics’ method of writing an iteration (or
repetition). In math we would say: “For the variable i starts at a given value
and repeats an action increasing the value of i until i is executed for the
stopping value”. Usually written in math as:
for i= 1 to 5 do some action
Note: here the = means equals not assignment. Another way to say it is that
i varies from 1 to 5.
Definitions
for
A test before iteration control structure typically used for counting.
Circular Nature of the Integer Data Type Family
An explanation of how modular arithmetic concepts apply to the integer
data type family and counting loops.
General Discussion
There are times when character and integer data types are lumped together
because they both act the same (often called the integer family). Maybe we
should say they act differently than the floating-point data types. The
integer family values jump from one value to another. There is nothing
between 6 and 7 nor between 'A' and 'B’. It could be asked why not make all
your numbers floating-point data types. The reason is twofold. First, some
things in the real world are not fractional. A dog, even with only 3 legs, is
still one dog not three fourths of a dog. Second, the integer data type is
often used to control program flow by counting (counting loops). The
integer family has a circular wrap around feature. Using a two byte integer,
the next number bigger than 32767 is negative 32768 (character acts the
same way going from 255 to 0. We could also reverse that to be the next
smaller number than negative 32768 is positive 32767. This can be shown
by using a normal math line, limiting the domain and then connecting the
two ends to form a circle.
Math Number Line
- infinity $$ + infinity
0
Two Byte Integer Domain
0
Circular Concept
-32,768 32,767
This circular nature of the integer family works for both integer and
character data types. In theory, it should work for the Boolean data type as
well; but in most programming languages it does not for various technical
reasons.
"In mathematics, modular arithmetic (sometimes called clock arithmetic) is
a system of arithmetic for integers where numbers "wrap around" after they
reach a certain value — the modulus. ...
A familiar use of modular arithmetic is its use in the 12 hour clock the
arithmetic of time-keeping in which the day is divided into two 12 hour
periods. If the time is 7:00 now, then 8 hours later it will be 3:00. Usual
addition would suggest that the later time should be 7 + 8 = 15, but this is
not the answer because clock time "wraps around" every 12 hours; there is
no "15 o'clock". Likewise, if the clock starts at 12:00 (noon) and 21 hours
elapse, then the time will be 9:00 the next day, rather than 33:00. Since the
hour number starts over when it reaches 12, this is arithmetic modulo 12.
+4h
Time-keeping on a clock gives an example of modular arithmetic."
(Modular arithmetic from Wikipedia)
The use of the modulus operator in integer division is tied to the concepts
used in modular arithmetic.
Implications When Executing Loops
If a programmer sets up a counting loop incorrectly, usually one of three
things happen:
e Infinite loop — usually caused by missing update attribute.
e Loop never executes — usually the text expression is wrong with the
direction of the less than or greater than relationship needing to be
switched.
e Loop executes more times than desired — update not properly handled.
Usually the direction of counting (increment or decrement) need to be
switched.
Let’s give an example of the loop executing for what appears to be for
infinity (the third item on our list).
Example:
C++ source code
for (ant x = 0 x =< 10). x--)
tL
cout << x << endl;
i
The above code accidently decrements and the value of x goes in a negative
way towards -2147483648 (the largest negative value in a normal four byte
signed integer data type). It might take a while (thus it might appear to be in
an infinite loop) for it to reach the negative 2 billion plus value, before
finally decrementing to positive 2147483647 which would, incidentally,
stop the loop execution.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo_ Circular Nature Integer.cpp
Definitions
circular nature
Connecting the negative and positive ends of the domain of an integer
family data type.
loop control
Making sure the attributes of a loop are properly handled.
modular arithmetic
A system of arithmetic for integers where numbers "wrap around".
Formatting Output
An explanation of formatting output (to cout) as used within a C++
program.
General Discussion
Formatting of output is handled in different ways in the various languages
used today. Many programming languages have different formatting
instructions for the standard output device which is usually the monitor
(going to a DOS black screen output box) versus using the monitor as a
Graphical User Interface (GUI). File storage output is often handled
similarly to the standard output device. All of this makes formatting of
output very machine, output device and language dependent.
When teaching programming fundamentals, many professors prefer to use
the standard output device. For the C++ programming language this means
going to the monitor using a DOS black screen output box.
C++ Considerations using Standard Output (cout)
Text Wrapping and Vertical Spacing
There are two items used to keep output from filling up a line and
wrapping on to the next line. They are:
e Using the escape code sequence of \n within your strings (text between
as set of double quote marks).
e Using the item from the iostream named: endl; which is short for end
line.
Thus the programmer is responsible for making text show reasonably on the
screen. Both of the above also allow for adequate vertical spacing when
needed in your output.
Handling Floating-point Data Type
It is nice to have your output displayed so humans can read it (most humans
are not use to scientific notation). There are three lines often inserted near
the start of your code (first items in the function main) that can be used to
direct the formatting of floating-point data. They are:
cout.setf(i0s::fixed);
cout.setf(1i0s::showpoint);
COUT; precision(n);
They do the following for the rest of your program:
e fixed — Do not use scientific notation but show floating-point values
like integer values (numeral digits of 0 to 9 — no exponent notation).
¢ showpoint — Always show a decimal point for floating-point values
even if there is no fractional part.
e precision — Always show this number of digits (change n to a number
like 2) to the right of the decimal point.
Setting the Width for Numbers
Setting the width for integer family and floating-point family data types
must be done for the output of each value. Assume in the following
example that age is an integer data type and money is a floating-point data
type.
cout << setw(4) << age << endl;
cout << setw(8) << money << endl;
Note that each value had to have its own setw(n) where n is an integer
number telling it how many positions to use for the output. The iomanip
header file (immediately shown) will need to be included in your program.
#include<iomanip> // needed for the setw
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo _ Formatting Output.cpp
Definitions
formatting
Modifying the way the output is displayed.
wrapping
When output is not vertically spaced properly.
Nested For Loops
An explanation of nesting with an example of nested for loops.
General Discussion
Nested Control Structures
We are going to first introduce the concept of nested control structures.
Nesting is a concept that places one item inside of another. Consider:
if expression
true action
else
false action
This is the basic form of the if then else control structure. Now consider:
if age is less than 18
you can't vote
if age is less than 16
you can't drive
else
you can drive
else
you can vote
if age is less than 21
youvcan’ © dimank
else
you can drink
As you can see we simply included as part of the "true action" a statement
and another if then else control structure. We did the same (nested another if
then else) for the "false action". In our example we nested if then else
control structures. Nesting could have an if then else within a while loop.
Thus, the concept of nesting allows the mixing of the different categories of
control structures.
Many complex logic problems require using nested control structures. By
nesting control structures (or placing one inside another) we can accomplish
almost any complex logic problem.
An Example — Nested for loops
Here is an example of a 12 by 12 multiplication table:
ae al REC |e macy ee a pea
Cae Soni sion yy aide tt does
ae vies een sal: Cn er iT
Soi, ote, aa aoe
oot Oe a ew) “ee CIaneea ea aia
Hoag) der OO ip 222) 24 ||
ae Sle, 26 || - Orel) sd oa eyetion pee ey
2 27 “80 See) “36ul
Ae Ande oo.) 020i) alg t|eoo aoa onl
32 | 36 | 40 | 44 | 48 |
5! 5] 10] 15] 20] 25 | 30] 35 |
40 | 45 | 50] 55 | 60 |
Gal: 160i: oi), 16.) 24T eo pneu lmese
48 | 54 | 60] 66] 72 |
Fie 7). tae 2a emiesS mea oe meaon|
56 | 63 | 70 | 77 | 84 |
Sy 9 lo 46 | 24°) 320 aos ase
64 | 72 |] 80 | 88 | 96 |
Gril 3Gril Mel. O74) .s6nasey ils ful moon
72) | ei) G00} “oo. |) dos |
10! 10] 20] 30 | 40 | 50] 60] 7o |
80 | 90 | 100 | 110 | 120 |
Tite “Sil 2or) vas4) 4. ESemmmesn mo
Sano Sn aon aaa
12 F122 2a 496 s4e eon rosa
96 | dos 420 | 132 4) a4 |
We might also see that the answers could be designed as a collection of
cells (each cell being exactly six spaces wide). The C++ source code to
produce the above is:
Example:
C++ source code: nested for loops - multiplication table
cour == ~ ee
for (acnress=1; across <137 acrosst+)
{
COU << Setw(4 << aevoss << - ||).
cout << endl;
cout << " 5
for(across=1; across <13; across++)
{
cout << "------ ‘
cout -<< endl;
for(down=1; down <13; downt++)
{
cout << setw(4) << down << " !";
for(across=1; across <13; across++)
cout << setw(4) << down*across << " |";
cout << endl;
}
cout << " ia
for (across=1; across<13; across++)
{
cout << setw(4) << across << " |";
}
cout << endl;
cout << " Wy
for (across=1; across<13; across++)
{
coun<c "=e
}
cout << endl;
for (down=1; down<13; down++)
{
cout << setw(4) << down << " !">
for (across=1; across<13; across++)
{
cout << setw(4) << down*across << " |";
}
cout << endl;
}
Colorized Code - multiplication table
a 1 | a 2 | 4 | = 6 | 7 1 8 | S | 20 Te) Be]
z } 2) 4 | 6 | s#) 4201 42) 341 61 20) 201 22 | 24
a! 3 | 6 | S| at i] wt atl 4 | at | aol aa | 36 |
4! 4 | 8) iy £6) 22 24) 26 | 22) 26) 22) 401 48
5 ! S| 2 | |) 20) 2 20) BS | 82] 25.| SO] SE | Be |
64 S| 22 | 2h BO] s&h 82 |) Sh) Se Goel BE.) Te
7 3 7 | 22) 22) cael] lhU6lU eT Ce] CUS Ue OTe | CO
8! 8 | 61 26 | St] 40.) 467 S86 | G2 | TE | BOT 86.) SE |
9! 9) if) 2 | S61 45)] SA) OO} I Bl} Se) 88:4 toe |
761 #248 | 20 | 30) 49 | SO. | 60} 7O | 8G] 90° | 100;) 20: | Ze |}
$2422 | 2b S|) OSA Se 1 SCE CT? CU. CBS SR oO Daa | Be |]
m2zi!i2i 24) 36 | @| 60 | 2 64 | 96 | 166 | 120°) 232 | 144 |
Colorized Output - multiplication table
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo Nested For Loops.cpp
Definitions
complex logic
Often solved with nested control structures.
Practice 15: Counting Loops
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Identify which selection control structures are commonly used a
counting loops.
3. Be able to write pseudo code or flowcharting for the for control
structure.
4. Be able to write C++ source code for a for control structure.
5. When feasible, be able to convert C++ source code from while loop
acting like a counting loop to a for loop and and vice versa.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Only for loops can be counting loops.
2. The integer data type has modular arithmetic attributes.
3. The escape code of \n is part of formatting output.
4. Nested for loops is not allowed in the C++ programming
language.
5. Counting loops use all four of the loop attributes.
Solution:
Answers:
1. false
2. true
3. true
4. false
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 15 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_15 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_15a.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Compile and run the Lab_15a.cpp source code file. Understand how it
works.
e Copy the source code file Lab_15a.cpp naming it: Lab_15b.cpp
e Convert the code that is counting (all four attributes) to a for loop.
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 15a — Instructions
Using proper C++ syntax, convert the following for loop to a while loop.
Example:
C++ source code
fon (xX = OF x = 1077545)
{
cou <= “Having Tun!
}
String Class within C++
An introduction to the string class within the C++ programming language.
General Discussion
In most programming languages a string is typically a string of characters
(string them along in a series). The rules for handling strings vary from
language to language. Technically, there is no string data type in the C++
programming language. However, the concept of a string data type makes it
easy to handle stings of character data. Associated with object oriented
programming the string class has been added to C++ as a standard part of
the programming language.
Most data is more complex than just one character, integer, etc.
Programming languages develop other methods to represent and store data
that are more complex. A complex data type of array is first most students
encounter. An array is a sequenced collection of elements of the same data
type with a single identifier name. This definition perfectly describes our
string data type concept. The simplest array is called a one-dimensional
array; also know as a list because we usually list the members or elements
vertically. However, strings are viewed as a one-dimensional array that
visualize as listed horizontally. Strings are an array of character data.
In the "C" programming language all strings were handled as an array of
characters that end in an ASCII null character (the value 0 or the first
character in the ASCII character code set). This changed with the
implementation of the string class within C++ where strings are stored as a
length controlled array with a maximum length of 255 characters. This
string class implementation also allowed programmers to use the reserved
word string as if it were a data type. Commonly used operators and some
alternatives for the string class are summarized in the following table:
C++
Operator
sizeof
. the
period
Operator
Name
assignment
Six
relational
addition
Usage how
many
bytes a
data type
occupies
class
member
String Class Implementation
Same as for standard data types
Same as for standard data types
Concatenation or Append
Implemented using a class member
function named length. Format:
identifier_name.length() NOTE: The
period between the identifier name and
the function name is the class member
operator.
Used in conjunction with class
functions
Most other operators are not allowed and basically do not make sense for a
string data type. The above items are demonstrated in the following
program.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo_ String Class.cpp
Definitions
array
A sequenced collection of elements of the same data type with a single
identifier name.
concatenation
Combining two strings into one string.
string class
A complex data item that uses object oriented programming.
class member
An operator used to invoke functions associated with a class.
Unary Positive and Negative Operators
An introduction to unary positive and unary negative operators used in
programming with details of C++ usage.
General Discussion
Unary positive also known as plus and unary negative also known as minus
are unique operators. The plus and minus when used with a constant value
represent the concept that the values are either positive or negative. Let’s
consider:
+5 + -2
We have three operators in this order: unary positive, addition, and unary
negative. The answer to this expression is a positive 3. As you can see, one
must differentiate between when the plus sign means unary positive and
when it means addition. Unary negative and subtraction have the same
problem. Let’s consider:
-2 - +5
The expression evaluates to negative 7. Let’s consider:
7 - -2
First constants that do not have a unary minis in front of them are assumed
(the default) to be positive. When you subtract a negative number it is like
adding, thus the expression evaluates to positive 9.
C++ Code Examples
The above examples work within the C++ programming language. What
happens if we put a unary positive or unary negative in front of a variable or
a named constant?
Negation — Unary Negative
The concept of negation is to take a value and change its sign, that is: flip it.
If it positive make it negative and if it is negative make it positive.
Mathematically, it is the following C++ code example, given that money is
an integer variable with a value of 6:
-money
money * -1
The above two expressions evaluate to the same value. In the first line, the
value in the variable money is fetched and then it’s negated to a negative 6.
In the second line, the value in the variable money is fetched and then it’s
multiplied by negative 1 making the answer a negative 6.
Unary Positive — Worthless
Simply to satisfy symmetry, the unary positive was added to the C++
programming language as on operator. However, it is a totally worthless or
useless operator and is rarely used. However don’t be confused the
following expression is completely valid:
6. to
The second + sign is interpreted as unary positive. The first + sign is
interpreted as addition.
money
+money
money * +1
For all three lines, if the value stored in money is 6 the value of the
expression is 6. Even if the value in money was negative 77 the value of the
expression would be negative 77. The operator does nothing, because
multiplying anything by 1 does not change its value.
Possible Confusion
Do not confuse the unary negative operator with decrement. Decrement
changes the value in the variable and thus is an Lvalue concept. Unary
negative does not change the value of the variable, but uses it in an Rvalue
context. It fetches the value and then negates that value. The original value
in the variable does not change.
Because there is no changing of the value associated with the identifier
name, the identifier name could represent a variable or named constant.
Exercises
Exercise:
Problem:
Evaluate the following items involving unary positive and unary
negative:
1. +10 - -2
2.-18 + 24
3.4-43
4.4+8+-+5
STOR ke
Solution:
Answers:
4. It’s 3. Surprised, but it works. The middle plus sign is addition
and the rest are unary positive or unary negative.
5. Error, no operand between addition and division.
Definitions
unary positive
A worthless operator almost never used.
unary negative
An operator that causes negation.
plus
Aka unary positive.
minus
Aka unary negative.
Practice 16: String Class, Unary Positive and Negative
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Identify which operators are allowed with the string class.
3. Understand the unary positive and unary negative operators.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Evaluate the following items involving unary positive and unary
negative:
1. +13 - -2
2.-10 + 14
3.4+-3
4.+8-* 45
Solution:
Answers:
L5
2.4
Bel
4. Error, no operand between subtraction and multiplication.
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 16 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_16 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab 16 Pseudocode.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file from the Lab_16_Pseudocode.txt file. Name
it: Lab_16.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 16a — Instructions
Describe the normal C++ operators allowed with the string data type.
Problem 16b — Instructions
Describe why unary positive is worthless.
Problem 16c — Instructions
Describe how unary negative works.
Conditional Operator
An introduction to the conditional operator as used within the C++
programming language.
Overview
The conditional operator is unique in that it has three operands separated by
two unconnected operator symbols. All other C++ operators are either
unary (one operator and one operand) or binary (one operator and two
operands). On the "Abbreviated Precedence Chart for C++ Operators" the
conditional operator has the word "trinary" in the comments column. This
prefix "tri" means three, thus three operands.
a :
. Meaning Comments
Operator
= rinary — thr rands with two
7 conditional trinary — three operand
operators
As an operator it produces a value for the expression. An easy way to
explain the conditional operator is to convert an "if then else" control
structure to an expression using the conditional operator.
Example:
if then else
if Cage 7)
cout << "You can vote.";
I
else
t
COUL <= “YOU can E Vote. |
i
Example:
conditional = option 1
age >= 17 ? cour << "You Can Vote. <= cout <<" you
can’t vote.";
Example:
conditional = option 2
COUR << "(age = 17 7 “Youlcan Vote. “s You cam t
vote.");
Note: The use of parenthesizes is needed because of the precedence of
operators. The conditional expression is of lower precedence than the
insertion (writing) operator.
The first operand is a test expression similar to those that control program
flow in control structures. This type of expression is also known as a
Boolean expression because they create a Boolean answer of true or false.
If the test is true the second operand becomes the value of the expression. If
false, the third operand becomes the value of the expression. The operators
of the question mark and colon separate the three operands.
Example:
general format
test expression ? expression true : expression
false
Definitions
conditional
A trinary C++ operator that acts like an if then else control structure.
Recursion vs Iteration
An introduction to recursion with the alternate method of using a for loop as
the solution to a repetitive algorithm. C++ programming code for factorial
is included.
Repetitive Algorithms
"In general, there are two approaches to writing repetitive algorithms. One
uses loops; the other uses recursion. Recursion is a repetitive process in
which a function calls itself. Both approaches provide repetition, and either
can be converted to the other's approach."[footnote] Iteration is one of the
categories of control structures. It allows for the processing of some action
zero to many times. Iteration is also known as looping and repetition. The
math term "to iterate" means to perform the statement parts of the loop.
Many problems/tasks require the use of repetitive algorithms. With most
programming languages this can be done with either:
Behrouz A. Forouzan and Richard F. Gilberg, Computer Science A
Structured Approach using C++ Second Edition (United States of America:
Thompson — Brooks/Cole, 2004) 265.
1. looping control structures, specifically the for loop (an iterative
approach)
2. recursive calling of a function
Using repetitive algorithms as the solution method occurs in many
mathematical oriented problems. These in include factorial, Fibonacci
numbers, and the Towers of Hanoi problem. Solutions to these problems are
often only presented in terms of using the recursive method. However, "...
you should understand the two major limitations of recursion. First,
recursive solutions may involve extensive overhead because they use
function calls. Second, each time you make a call you use up some of your
memory allocation. If the recursion is deep — that is, if there is a large
number of recursive calls — then you may run out of memory. Both the
factorial and Fibonacci numbers solutions are better developed iteratively.’
[footnote]
Behrouz A. Forouzan and Richard F. Gilberg, Computer Science A
Structured Approach using C++ Second Edition (United States of America:
Thompson — Brooks/Cole, 2004) 272.
Understanding how recursion or the iterative approaches work will be left
to others. They are usually covered in detail as part of studying data
structures. Our goal in covering them is to:
1. Provide you with a definition of recursion
2. Introduce the alternate solution approach of iteration
The following demonstration program shows both solutions for 8! (eight
factorial).
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo_Factorial.cpp
Definitions
recursion
A repetitive process in which a function calls itself.
factorial
A math problem that often is solved using recursion.
Practice 17: Conditional Operator and Recursion
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Understand the conditional operator and how it works.
3. Understand recursion as a problem solving technique.
4. When feasible, be able to convert C++ source code from a conditional
expression to an if then else and vice versa.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. The conditional expression acts like a case structure.
2. The conditional operator is a two part operator with three
operands.
3. Recursion is one method of implementing a repetitive algorithm.
4. Recursion is always preferred over an iterative approach to a
repetitive problem.
5. Factorial is usually demonstrated with an iterative approach.
Solution:
Answers:
1. false
2. true
3. true
4. false
5. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 17 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_17 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_17a.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
Compile and run the Lab_17a.cpp source code file. Understand how it
works.
Copy the source code file Lab_17a.cpp naming it: Lab_17b.cpp
Convert the code that is using the if then else to a conditional
expression.
Convert the code that is using the conditional expression to an if then
else.
Build (compile and run) your program.
After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 17a — Instructions
Using proper C++ syntax, convert the following if then else to a conditional
expression.
Example:
if then else
Hote
iu
Z
(x == y)
Seve
Problem 17b — Instructions
Using proper C++ syntax, convert the following conditional expression to
an if then else.
Example:
conditional
answer = y < Z ? 47 : 92;
Array Data Type
An introduction to the array data type with some examples in the C++
programming language.
Overview
An array is a sequenced collection of elements of the same data type with a
single identifier name. As such, the array data type belongs to the
"Complex" category or family of data types. Arrays can have multiple axes
(more than one axis). Each axis is a dimension. Thus a single dimension
array is also known as a list. A two dimension array is commonly known as
a table (a spreadsheet like Excel is a two dimension array). In real life there
are occasions to have data organized into multiple dimensioned arrays.
Consider a theater ticket with section, row and seat (three dimensions). This
module will only cover the single dimension array. Most single dimension
arrays are visualized vertically and are often called a list.
Most programmers are familiar with a special type of array called a string.
Strings are basically a single dimension array of characters. Unlike other
single dimension arrays, we usually envision a string as a horizontal stream
of characters and not vertically as a list. Within C++ the string data type is a
length-controlled array and is a pre-defined data class.
We refer to the individual values as members (or elements) of the array.
Programming languages implement the details of arrays differently.
Because there is only one identifier name assigned to the array, we have
operators that allow us to reference or access the individual members of an
array. The operator commonly associated with referencing array members is
the index operator. It is important to learn how to define an array and
initialize its members. Additionally, the sizeof operator is often used to
calculate the number of members in an array.
Defining an Array in C++
Example:
int ages[5] = {49,48, 26,19, 16};
This is the defining of storage space. The square brackets (left [ and right
]) are used here to create the array with five integer members and the
identifier name of ages. The assignment with braces (that is a block)
establishes the initial values assigned to the members of the array. Note the
use of the sequence or comma operator. We could have done it this way:
int ages[] = {49,48,26,19,16};
By leaving out the five and having initial values assigned, the compiler will
know to create the array with five storage spaces because there are five
values listed. This method is preferred because we can simply add members
to or remove members from the array by changing the items inside of the
braces. We could have also done this:
int ages[5];
This would have declared the storage space of five integers with the
identifier name of ages but their initial values would have been unknown
values (actually there would be values there but we don’t know what they
would be and thus think of the values as garbage). We could assign values
later in our program by doing this:
ages[O]| = 49;
ages[1] = 48;
ages[2] = 26;
ages[3] = 19;
ages[4] = 16;
Note:The members of the array go from 0 to 4; NOT 1 to 5. This is
explained in more detail in another Connexions module that covers
accessing array members and is listed in the supplemental links provided.
See: Array Index Operator.
Definitions
dimension
An axis of an array.
list
A single dimension array.
table
A two dimension array.
Array Index Operator
An introduction to the array index operator as used within the C++
programming language.
Array Index Operator in C++
Example:
int ages[5] = {49,48, 26,19, 16};
int my_age;
my_age = ages[2]
This second usage of the square brackets is as the array notation of
dereference or more commonly called the index operator. As an operator
it either provides the value held by the member of the array (Rvalue) or
changes the value of member (Lvalue). In the above example the member
that is two offsets from the front of the array (the value 26) is assigned to
variable named my_age. The dereference operator of [2] means to go the
2"¢ offset from the front of the ages array and get the value stored there. In
this case the value would be 26. The array members (or elements) are
referenced starting at zero. The more common way for people to reference a
list is by starting with one. Many programming languages reference array
members starting at one, however for some languages (and C++ is one of
them) you will need to change your thinking. Consider:
Position C++ mae ; om
America Contests
zero offsets from the ages Wanner 15t Place
front [0]
one offsets from the ages 15t Runner 2nd Place
front [1] Up
two offsets from the ages 2d Runner 3" Place
front [2] Up
three offsets from the ages 3™ Runner Ath Place
front [3] Up
four offsets from the ages 44 Runner sth Place
front [4] Up
Saying that my cousin is the 2’ Runner Up in the Miss America contest
sounds so much better than saying that she was in 3™ Place. We would be
talking about the same position in the array of the five finalists.
ages[3] = 20;
This is an example of changing an array’s value by assigning 20 to the 4"
member of the array and replacing the value 19 with 20. This is an Lvalue
context because the array is on the left side of the assignment operator.
The C++ operator name is called the array index or simply the index
operator and it uses the square brackets as the operator symbols.
Definitions
array member
An element or value in an array.
index
An operator that allows us to reference a member of an array.
offset
The method of referencing array members by starting at zero.
Displaying Array Members
Examples of displaying members of an array with for loops and using the
sizeof operator within the C++ programming language.
Accessing Array Members in C++
Example:
accessing the members of an array
int ages) = (49,48, 26,19, 16):
it COUntLeR ;
for (counter = 0, counter < 5, counter++)
{
cout << ages[counter] << endl;
}
This second usage of the square brackets is as the array notation of
dereference or more commonly called the index operator. As an operator
it provides the value held by the member of the array. For example, during
one of the iterations of the for loop the index (which is an integer data type)
will have the value of 3. The expression ages[counter] would in essence be:
ages[3]. The dereference operator of [3] means to go the 3" offset from the
front of the ages array and get the value stored there. In this case the value
would be 19. The array members (or elements) are referenced starting at
zero. The more common way for people to reference a list is by starting
with one. Many programming languages reference array members starting
at one, however for some languages (and C++ is one of them) you will need
to change your thinking. Consider:
Miss Other
iti ++
Position C Amneuiea Contests
zero offsets from the ages Wannes 15 Place
front [0]
st
one offsets from the ages 1* Runner and Place
front [1] Up
nd
two offsets from the ages 2° Runner 314 Place
front [2] Up
rd
three offsets from the ages 3° Runner Ah Place
front [3] Up
th
four offsets from the ages 4™ Runner sth place
front [4] Up
Saying that my cousin is the 2" Runner Up in the Miss America contest
sounds so much better than saying that she was in 3™ Place. We would be
talking about the same position in the array of the five finalists.
Rather than using the for loop to display the members of the array, we could
have written five lines of code as follows:
cout << ages[0]| << endl;
cout << ages[1] << endl;
cout << ages[2]| << endl;
cout << ages[3]| << endl;
cout << ages[4] << endl;
Using the Sizeof Operator with Arrays in C++
Example:
using the sizeof operator
int ages[] = {49,48, 26,19, 16};
int counter;
for (counter = 0, counter < sizeof ages / sizeof
ages[O], counter++)
cout << ages[counter] << endl;
}
Within the control of the for loop for the displaying of the grades, note that
we calculated the number of the members in the array by using the sizeof
operator. The expression is:
sizeof ages / sizeof ages[0|
When you ask for the sizeof an array identifier name the answer is how
many total bytes long is the array (or in other words — how many bytes of
storage does this array need to store its values). This will depend on the
data type of the array and the number of elements. When you ask for the
sizeof one of its members, it tells you how many bytes one member needs.
By dividing the total number of bytes by the size of one member, we get the
answer we want: the number of members in the array. This method allows
for flexible coding. By writing the for loop in this fashion, we can change
the declaration of the array by adding or subtracting members and we don't
need to change our for loop code.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo_Arrays.cpp
Definitions
flexible coding
Using the sizeof operator to calculate the number of members in an
array.
Practice 18: Introduction to Arrays
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Within C++ source code be able to define a single dimension array.
3. Within C++ source code be able to access array members using the
index operator.
4. Within C++ source code be able to calculate the number of members in
an array using the sizeof operator.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. The array data type is one of the standard data types in C++.
2. Arrays can have more than one dimension.
3. For loops are often used to display the members of an array.
4. When defining an array, it is preferable to specify how many
members are in the array.
5. Arrays are rarely used to represent data.
Solution:
Answers:
1. false
2. true
3. true
4. false
5. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 18 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_18 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_18 Narrative Description.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
¢ Create a source code file following the directions in the
Lab_18_Narrative_Description.txt file. Name it: Lab_18.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 18a — Instructions
Briefly explain what an array is and list the two common operators used
with arrays.
File Input and Output
An introduction to file input and output with examples within the C++
programming language.
Overview of File I/O in C++
We need to understand how to open, read, write and close text files. The
following File Input/Output terms are explained:
Text File — A file consisting of characters from the ASCII character code
set. Text files (also know an ASCII text files) contain character data. When
we create a text file we usually think of it consisting of a series of lines. On
each line are several characters (including spaces, punctuation, etc.) and we
generally end the line with a return (this a character within the ASCII
character code set). The return is also known as the new line character. You
are most likely already familiar with the escape code of \n which is used
within C++ to indicate a return character when used with in a literal string
with the cout.
A typical text file consisting of lines can be created by text editors
(Notepad) or word processing programs (Microsoft Word). When using a
word processor you must usually specify the output file as text (.txt) when
saving it. Most source code files are ASCII text files with a unique file
extension; such as C++ using .cpp, Pascal using .pas, Cobol using .cob, etc.
Thus, most compiler/Integrated Development Environment software
packages (such as the Bloodshed Dev-C++ 5 compiler/IDE) can be used
to create ASCII text files.
Filename — The name and its extension. Most operating systems have
restrictions on which characters can be used in filenames. Example for MS-
DOS and Windows: Lab_05.txt
Because some operating systems do not allow spaces, we suggest that you
use the underscore where needed for spacing in a filename.
Filespec — The location of a file along with its filename. It is short for file
specification. Most operating systems have a set of rules on how to specify
the drive and directory (or path through several directory levels) along with
the filename. Example for MS-DOS and Windows:
C:\myfiles\cosc_1436\Lab_05.txt
Because some operating systems do not allow spaces, we suggest that you
use the underscore where needed when creating folders or sub-directories.
Open — Your program requesting the operating system to let it have access
to an existing file or to open a new file. Within C++ this is accomplished by
including the header file: <fstream> File Input/Output is handled in C++ by
using a pre-defined class of data objects, similar to the way string data type
is handled. This class of objects has both data type names and functions
built to specifically accomplish opening and closing a file.
Within your program you create a local storage variable with the data type
of fstream like this:
fstream inData;
This variable will be used to store the device token that the operating
system assigns to the file being opened. Thus, opening a file uses a class
member function call like this:
inData.open( "C:\\myfiles\\cosc_1436\\Lab_05. txt",
essen
The two parameters passed to the function are the filespec and the method
that you want to use the file (in this example as input). The function
provides a returning value of a device token from the operating system and
it is stored in the variable named inData.
It is considered good programming practice to determine if the file was
opened properly. The device token should be a non zero value. It the
operating system gives you the value of zero it was not able to open the file.
The reason it usually can't open a file is because the filespec is wrong
(misspelled or not typed case consistent in some operating systems) or the
file is not stored in the location specified. We often test the device token by
using an if then control structure with the action consisting of stopping the
program if it is true that you got the zero. The first line of the if then control
structure looks like this:
if (!inData)
Don’t be misled by the not operator. This reads "if it is true that the token
stored in inData is zero". If inData is zero, noting zero is 1 or true.
Read — Moving data from a device that has been opened into a memory
location defined in your program. When reading text files that have integer
or floating-point constants, the operating systems converts the text symbols
to a binary number. The operator used is the extraction or read operator. An
example of reading is:
inData >> next_number
This expression is similar to reading from the standard input device (aka the
keyboard):
cin >> next_number
The "cin" is a predefined device token associated with the Standard Input
and Output devices. For our file reading example you might say, "Go to the
device identified by the token stored in the inData variable and read in the
next value storing it in the next_number variable within my program".
Write — Moving data from a memory location defined in your program to a
device that has been opened. When writing integer or floating-point data
types, the operating system converts the binary number into the proper text
symbols. The operator used is the insertion or write operator. An example
of writing is:
outData << "Total is: " << total << endl;
This expression is similar to writing to the standard output device (aka the
monitor):
couk << "Total as: " << total << endl;
The "cout" is a predefined device token associated with the Standard Input
and Output devices. For our file writing example you might say, "Go to the
device identified by the token stored in the outData variable and write the
items listed (the string constant then the value stored in my program
variable named total then the endl or new line or the return character)".
Close — Your program requesting the operating system to release a file that
was previously opened. There are two reasons to close a file. First, it
releases the file and frees up the associated operation system resources.
Second, if closing a file that was opened for output; it will clear the out the
operating system’s buffer and insure that all of the data is physically stored
in the output file. Some examples of closing files:
inData.close();
outData.close();
You need to study this module in conjunction with the demo file provided.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo File IO.cpp
Download from Connexions: Demo File IO Input.txt
After you run the program use a text editor to examine the
Demo_File_IO_Output.txt file created by the program. You should see the
output as: TOtal is: 33.3
Definitions
text file
A file consisting of characters from the ASCII character code set.
filename
The name and its extension.
filespec
The location of a file along with its filename.
open
Your program requesting the operating system to let it have access to
an existing file or to open a new file.
device token
A key value provided by the operating system to associate a device to
your program.
read
Moving data from a device that has been opened into a memory
location defined in your program.
write
Moving data from a memory location defined in your program to a
device that has been opened.
close
Your program requesting the operating system to release a file that was
previously opened.
Arrays and Functions
An introduction to processing arrays with functions with an example of
displaying an array within the C++ programming language.
Overview of Array Functions
Arrays are an important complex data type used in almost all programming.
We continue to concentrate on simple one dimension arrays also called a
list. Most programmers develop a series of user defined specific task
functions that can be used with an array for normal processing. These
functions are usually passed the array along with the number of elements
within the array. Some of functions also pass another piece of data needed
for that particular functions task.
This module covers the displaying the array members on the monitor via
calling an array function dedicated to that task. You need to study this
module in conjunction with the demo file provided.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials.
Download from Connexions: Demo _Array_Display_Function.cpp
Definitions
array function
A user defined specific task function designed to process an array.
Loading an Array from a File
An introduction and example of loading an array from a file within the C++
programming language.
Conceptual Overview
Loading an array from a file presents an interesting dilemma. The problem
resolves around how many elements you should plan for in the array. Let’s
say 100, but what if the file has fewer or more than 100 values. How can
the program handle it correctly?
The solution involves some simple steps:
1. We can read the file once to get the element count. Thus, we will know
exactly how many members (elements) we will need.
2. We can then create an array using dynamic memory allocation by
defining the array within a function so that it has local scope. Local
scope variables are created during the execution of the program and
use the stack as the storage location instead of the data area. If you
define the array outside of a function (global scope also known as
static memory allocation) it stores it in the data area and must know
how much storage space to allocate to the array when you write the
source code. Since we don’t know how many elements will be on the
input file when we write the source code defining an array with global
scope will not work. But, we can determine exactly how many
members we need for the array by having our program count them
(step 1) so that we can then define the array with local scope to the
precise size needed.
3. We can then load the array by reading the file a second time and
storing the values read into the array just created.
This method is demonstrated in the demo file provided, thus you need to
study this material in conjunction with the demo program.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo Loading Array_from File.cpp
Download from Connexions: Demo Farm Acres Input.txt
Definitions
dynamic memory
Aka stack created memory associated with local scope.
static memory
Aka data area memory associated with global scope.
Math Statistics with Arrays
An introduction to functions performing statistical calculations on an array
within the C++ programming language.
Overview
Arrays are an important complex data type used in almost all programming.
We continue to concentrate on simple one dimension arrays also called a
list. Most programmers develop a series of user defined specific task
functions that can be used with an array for normal processing. These
functions are usually passed the array along with the number of elements
within the array. Some of functions also pass another piece of data needed
for that particular functions task.
This module covers the totaling of the members of an integer array member.
The Latin name for totaling is summa sometimes shortened to the word
sum. The array function is often called "sum" and it does some parameter
passing. It passes into the function the common two items of the array: its
name along with the number of elements; but it also returns a value
representing sum or total of the values within the array. You need to study
this module in conjunction with the demo file provided.
Other mathematical functions often associated with statistics such as:
average, count, minimum, maximum, standard deviation, etc. are often
developed for processing arrays.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo Sum _ Array Function.cpp
Download from Connexions: Demo Farm Acres Input.txt
Definitions
sum
Latin for summa or a total.
Practice 19: File I/O and Array Functions
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Within C++ source code be able to understand basic file input and file
output.
. Understand why we test to see if a file was opened properly.
. Understand why we close a file when we are done with it.
5. Within C++ source code be able to understand functions for arrays,
specifically counting the number of elements in a file so you can
define an array, load that array with those elements, display the array
and sum the array.
6. Within C++ source code be able to create functions for arrays,
specifically a function for averaging.
& WwW
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Text files are hard to create.
2. A filespec refers to a very small (like a spec dust) file.
3. A device token is a special non zero value the operating system
gives your program and is associated with the file that you
requested to be opened.
4. Programmers should not worry about closing a file.
5. Where you define an item, that is global or local scope, is rarely
important.
Solution:
Answers:
1. false
2. false
3. true
4. false
5. false
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 19 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_19 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_19 Narrative Description.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file following the directions in the
Lab_19_Narrative_Description.txt file. Name it: Lab_19.cpp
¢ Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 19a — Instructions
For what purpose do we use the sizeof operator with an array.
Problem 19b — Instructions
Why would we open a file and count its elements and then close the file.
Finding a Specific Member of an Array
An introduction and example of searching an array within the C++
programming language.
Overview
Finding a specific member of an array means searching the array until the
member is found. It's possible that the member does not exist and the
programmer must handle that possibility within the logic of his algorithm.
Two specific searches can be made for the maximum (largest) values in the
array or the minimum (smallest) value in the array. Maximum and
minimum are also know as max and min.
There are two basic ways of searching for a specific value:
1. Linear search
2. Binary search
"The linear search is a very simple algorithm. Sometimes called a
sequential search, it uses a loop to sequentially step through an array,
starting with the first element. It compares each element with the value
being search for, and stops when either the value is found or the end of the
array is encountered. If the value being searched for is not in the array, the
algorithm will search to the end of the array."[footnote]
Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++
Early Objects Sixth Edition (United States of America: Pearson — Addison
Wesley, 2008) 559.
Binary search is not cover in this module. Linear search and searching for
the maximum is demonstrated in the demo file provided, thus you need to
study this material in conjunction with the demo program.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo Farm Acres Input.txt
Definitions
linear search
Using a loop to sequentially step through an array.
maximum
Aka max or the largest member of an array.
minimum
Aka min or the smallest member of an array.
Sorting an Array
An introduction and example of sorting an array within the C++
programming language.
Overview
Sorting is the process through which data are arranged according to their
values. There are several sorting algorithms or methods that can be used to
sort data. Some include:
1. Bubble
2. Selection
3. Insertion
We will not be covering the selection or insertion sort methods in this
module.
"The bubble sort is an easy way to arrange data in ascending or descending
order. If an array is sorted in ascending order, it means the values in the
array are stored from lowest to highest. If values are sorted in descending
order, they are stored from highest to lowest. Bubble sort works by
comparing each element with its neighbor and swapping them it they are
not in the desired order." [footnote |
Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++
Early Objects Sixth Edition (United States of America: Pearson — Addison
Wesley, 2008) 569.
There are several different methods of bubble sorting and some methods are
more efficient than others. Most use a pair of nested loops or iteration
control structures. One method sets a flag that indicates that the array is
sorted, then does a pass and if any elements are exchanged (switched); it
sets the flag to indicate that the array is not sorted. It is executed until it
makes a pass and nothing is exchanged.
This bubble sort sets a flag that indicates that the array is sorted (that is it does not need
more sorting), then does a pass and if any elements are exchanged (switched); it sets the
flag to indicate that the array is not sorted (that is it needs more sorting). The outer do
while loop is executed until the inner for !oop makes a pass and nothing is exchanged.
Here is some color highlighted C++ code from Demo_Sort_Array_Function.cpp
do
{
moresortneeded = false:
for(int i = 0: i < array_size - 1: it+)
{
if (things[i] > things[it+1])
{
temp = things[il]:
things[i] = things[it1]:
things[it+1] = temp:
moresortneeded = true:
}
}
}
while (moresortneeded) :
The bubble sort gets its name from the lighter bubbles that move or "bubble
up" to the top of a glass of soda pop. We move the smaller elements of the
array to the top as the larger elements move to the bottom of the array. This
can be viewed from a different perspective. Using an Italian salad dressing
with oil, water and herbs; once shaken you can either:
1. envision the lighter oil rising to the top; OR
2. envision the heaver water and herbs sinking to the bottom
Either way is correct and this version of the code simply demonstrates the
sinking to the bottom the heaver or larger elements of the array.
Bubble sorting is demonstrated in the demo file provided, thus you need to
study this material in conjunction with the demo program.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo _ Sort Array_Function.cpp
Download from Connexions: Demo Farm Acres Input.txt
Definitions
sorting
Arranging data according to their values.
bubble sort
A method of swapping array members until they are in the desired
sequence.
Practice 20: More Array Functions
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Within C++ source code be able to understand functions for arrays,
specifically searching a array's values to see if a given value exists,
finding the maximum value in an array and sorting an array.
3. Within C++ source code be able to create functions for arrays,
specifically a function for finding the smallest value in an array.
4. Within C++ source code be able to modifying existing code to process
different types of arrays.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Linear searches require complex algorithms.
2. Functions are often created for searching for the max and min
values in an array.
3. The bubble sort is an easy way to arrange data an array.
4. There is only one method of bubble sorting.
5. Sorting an array is frequently done.
Solution:
Answers:
1. false
2. true
3. true
4. false
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 20 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_20 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_20 Narrative Description.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
¢ Create a source code file following the directions in the
Lab_20_Narrative_Description.txt file. Name it: Lab_20.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 20a — Instructions
Give a short explanation of bubble sorting.
Versatile Code with Typedef
An explanation and example creating versatile code using typedef within
the C++ programming language.
Overview
Everyone seeks of ways to be more efficient in what they do. A farmer uses
a tractor instead of a horse. A construction worker uses an air powered nail
gun instead of a hammer. Programmers are no different than others, in that
they are constantly improving their ability to produce correctly working
programs. Some aspect of this is the use of modular/structured
programming, proper documentation and following industry rules for a
specific programming language. One example of efficient coding is letting
the computer count the number of elements in an array. If we define an
array:
Titmages lau sene2 aoa
We can use the following expression to calculate the number of members in
the array:
sizeof ages / sizeof ages|[0]|
This type of flexible coding allows us to change the members of the array
by adding or subtracting a values, like this:
ine ages | = (51007 o2 ok:
Thus, we don't have to modify our code that uses the expression that
calculates the number of member in the array.
One use of the typedef is to allow us to write code that can be quickly
changed to handle different data types. There are several integer and
floating-point data types that all store number values with different
domains. If we write our code using some typedef statement, then our code
becomes versatile. By changing only our typedef commands, our code can
be used to process data of a different data type. This is demonstrated within
the demo file provided, thus you need to study this material in conjunction
with the demo program.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo_Versatile Array_Functions.cpp
Download from Connexions: Demo Farm Acres Input.txt
Download from Connexions: Demo Deposit Checks Input.txt
Definitions
versatile
Easily modifying code to handle another data type.
flexible coding
Using the sizeof operator to calculate the number of members in an
array.
typedef
Allows the programmer to create an alias, or synonym, for an existing
data type.
Practice 21: More on Typedef
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Understand how typedef is used within C++ source code be able make
the code versatile that is easy to change for different data types.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Most programmers rarely worry about efficiency.
2. Modular/structured programming helps improve efficiency.
3. Flexible coding helps improve efficiency.
4. Who cares about indentation and alignment within source code.
It’s a waste of time.
5. Versatile code is a concept that is easy to understand.
Solution:
Answers:
1. false — Efficiency of code execution, no; efficiency of code
production and maintenance, yes.
true
. true
false
. maybe true and maybe false — It does require some effort to catch
on to how it works.
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 18 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_21 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab 21 Narrative Description.txt
Download from Connexions: Lab_21 Input.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Create a source code file following the directions in the
Lab_21_Narrative_Description.txt file. Name it: Lab_21.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 21a — Instructions
Explain the difference between flexible coding and versatile coding.
Address Operator
An introduction to the address operator as used within the C++
programming language.
Address Operator in C++
"Every variable is assigned a memory location whose address can be
retrieved using the address operator &. The address of a memory location is
called a pointer. Every variable in an executing program is allocated a
section of memory large enough to hold a value of that variable’s type."
[footnote] Thus, whether the variables are global scope and use the data
area for storage or local scope and use the stack for storage; you can ask the
question at what address in the memory does this variable exist. Given an
integer variable named age:
Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++
Early Objects Sixth Edition (United States of America: Pearson — Addison
Wesley, 2008) 597.
int age = 47;
We can use the address operator [which is the ampersand or &] to
determine where it exists (or its address) in the memory by:
&age
This expression is a pointer data type. The concept of an address and a
pointer are one in the same. A pointer points to the location in memory
because the value of a pointer is the address were the data item resides in
the memory.
The address operator is commonly used in two ways:
1. To do parameter passing by reference
2. To establish the value of pointers
Both of these items are covered in the supplemental links to this module.
You can print out the value of the address with the following code:
COouL << Gage;
This will by default print the value in hexadecimal. Some people prefer an
integer value and to print it as an integer you will need to cast the address
into a long data type:
cout << long(&age);
One additional tidbit, an array’s name is by definition a pointer to the arrays
first element. Thus:
Tt gs i) {i22, Teh, asd O77:
establishes "iqs" as a pointer to the array.
Definitions
address operator
The ampersand or &.
pointer
A variable that holds an address as its value.
Parameter Passing by Reference
An introduction and example of parameter passing by reference as used
within the C++ programming language.
Overview
When we pass parameters to functions we usually pass by value; that is the
calling function provides several values to the called function as needed.
The called function takes these values which have local scope and stores
them on the stack using them as needed for whatever processing the
functions accomplishes. This is the preferred method when calling user
defined specific task functions. The called function passes back a single
value as the return item if needed. This has the advantage of a closed
communications model with everything being neatly passed in as values
and any needed item returned back as a parameter.
By necessity there are two exceptions to this closed communications model:
1. When we need more than one item of information returned by the
function
2. When a copy of an argument cannot reasonably or correctly be made
(example: file stream objects).
These exceptions are handled by parameter passing by reference instead of
passing a value. The item passed is called a reference variable and it
represents a concept of an alias for the variable. Any change made to the
reference variable is actually performed on the variable that it represents.
The symbol of the ampersand is used to designate the reference variable
(and it is associated with the address operator).
Example:
parameter passing by reference
// prototype
void process_values(int qty_dimes, int
qty_quarters, double &value_dimes, double
&value_quarters);
// variable definitions
int dimes = 45;
pelle quarters = 33;
double value_dimes;
double value_quarters;
// somewhere in the function main
process _values(dimes, quarters, value_dimes,
value_quarters);
// definition of the function
void process_values(int qty_dimes, int
qty_quarters, double &value_dimes, double
&value_quarters);
{
value_dimes = dimes * 0.10;
value_quarters = quarters * 0.25;
i
Note:The ampersand must appear in both the prototype and the function
definition but it does not appear in the function call.
The above example shows the basic mechanics of parameter passing by
reference. You should study the demonstration program in conjunction with
this module.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo Parameter _Passing.cpp
Definitions
reference variable
Used with parameter passing by reference.
Pointer Data Type
An introduction to the pointer data type as used within the C++
programming language.
Pointer Data Type in C++
A pointer variable is a variable that holds the address of a memory
location. "Every variable is assigned a memory location whose address can
be retrieved using the address operator &. The address of a memory
location is called a pointer."[footnote] The pointer data type allows us to
designate a variable to hold an address or a pointer. The concept of an
address and a pointer are one in the same. A pointer points to the location in
memory because the value of a pointer is the address were the data item
resides in the memory. Given an integer variable named age:
Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++
Early Objects Sixth Edition (United States of America: Pearson — Addison
Wesley, 2008) 597.
int age = 47;
We can create a pointer variable and establish its value which would be the
done using the address operator [which is the ampersand or &] by:
int * int_pointer = &age;
The asterisk is used to designate that the variable int_pointer is an integer
pointer [int *]. This means that whenever we use the variable int_pointer
that the compiler will know that it is a pointer that points to an integer.
In order to use pointers you will need to understand the indirection
operator which is covered a supplemental link.
Definitions
pointer
A variable that holds an address as its value.
Indirection Operator
An introduction to the indirection operator as used within the C++
programming language.
Indirection Operator in C++
When we pass parameters to functions we usually pass by value; that is the
calling function provides several values to the called function as needed.
The called function takes these values which have local scope and stores
them on the stack using them as needed for whatever processing the
functions accomplishes. This is the preferred method when calling user
defined specific task functions. The called function passes back a single
value as the return item if needed. This has the advantage of a closed
communications model with everything being neatly passed in as values
and any needed item returned back as a parameter.
By necessity there are two exceptions to this closed communications model:
1. When we need more than one item of information returned by the
function
2. When a copy of an argument cannot reasonably or correctly be made
(example: file stream objects).
These exceptions could be handled by parameter passing by reference
instead of passing a value. Although different syntax than parameter
passing when using a reference variable; using a pointer variable and the
indirection operator can accomplish the same effect. The indirection
operator is the asterisk or the character that we also use for multiplication.
The concept of indirection is also known as dereferencing, meaning that
we are not interested in the pointer but want the item to which the address is
referring or referencing.
Example:
parameter passing with pointers
// prototype
void process_values(int qty_dimes, int
qty_quarters, double * ptr_value_dimes, double *
ptr_value_quarters);
// variable definitions
BW Ai dimes = 45;
aula) quarters = 33;
double value_dimes;
double value_quarters;
double * ptr_value_dimes = &value_dimes;
double * ptr_value_quarters = &value_quarters;
// somewhere in the function main
process _values(dimes, quarters, ptr_value_dimes,
ptr_value_quarters);
// definition of the function
void process_values(int qty_dimes, int
qty_quarters, double * ptr_value_dimes, double *
ptr_quarters);
* ptr_value_dimes = dimes * 0.10;
* ptr_value_quarters = quarters * 0.25;
}
Note:The asterisk and must appear in both the prototype and the function
definition when defining the pointer variables but it does not appear in the
function call when the pointers are passed into the function.
The above example shows the basic mechanics of the indirection operator.
The use of pointers with indirection is often preferred for processing arrays.
The array index operator is also known as the array method of
dereferencing. The following couts are equivalent:
int ages! | =] 147,455 18, di, ov
cout << ages[3];
cout << *(ages + 3);
The both say, "The name of an array is a pointer; take the pointer and
calculate a new address that points to the 3 offset by adding the correct
number of bytes onto the pointer (integer data type is normally 4 bytes long
— 3 offsets times 4 bytes is 12 bytes); then dereference that pointer (since
this is an Rvalue context — fetch me the value that you are pointing at) and
send it to the standard output device."
You should study the demonstration programs in conjunction with this
module.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo_ Pointer Passing.cpp
Download from Connexions: Demo Array Pointer Processing.cpp
Definitions
indirection operator
The asterisk used for dereferencing a pointer.
dereferencing
The concept of using the item to which a pointer or address is pointing
at.
Practice 22: Pointers
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Acquire a general understanding of the pointer data type, the address
and indirection operators, the concept of dereferencing.
3. Given pseudocode, write the C++ code for a program that uses
reference variables.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. The address operator is the @ symbol.
2. Passing by reference should be used when there is only one item
to be modified.
3. Variables of pointer data type are defined using an asterisk.
4. Using pointers with the indirection operator can be used instead
of passing variables by reference.
5. There are two kinds of dereferencing — one with the indirection
operator and the other with the index operator.
Solution:
Answers:
1. false
2. false
3. true
4. true
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 22 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_22 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab 22 Pseudocode.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
¢ Create a source code file from the Lab_22_Pseudocode.txt file. Name
it: Lab_22.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 22a — Instructions
Give a general explanation of the pointer data type and the use of addresses
and dereferencing. Include both the indirection operator and the index
operator in your discussion.
Multidimensional Arrays
An introduction and example of multidimensional arrays as used within the
C++ programming language.
Overview
An array is a sequenced collection of elements of the same data type with a
single identifier name. As such, the array data type belongs to the
"Complex" category or family of data types. Arrays can have multiple axes
(more than one axis). Each axis is a dimension. Thus a single dimension
array is also known as a list. A two dimension array is commonly known as
a table (a spreadsheet like Excel is a two dimension array). In real life there
are occasions to have data organized into multiple dimensioned arrays.
Consider a theater ticket with section, row and seat (three dimensions).
We refer to the individual values as members (or elements) of the array.
Programming languages implement the details of arrays differently.
Because there is only one identifier name assigned to the array, we have
operators that allow us to reference or access the individual members of an
array.
The operator commonly associated with referencing an array member is
the index operator. It is important to learn how to define an array and
initialize its members. The index operator is a set of square brackets with an
integer value between the brackets that represents the offset from the front
of the array.
Multidimensional arrays use one set of square brackets per dimension or
axis of the array. For example a table which has two dimensions would use
two sets of square brackets to define the array variable and two sets of
square brackets for the index operators to access the members of the array.
Because of the complexity for multidimensional arrays, the demonstration
program shows a two dimension array and you should study it in
conjunction with this module.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo Multidimension Arrays.cpp
Definitions
dimension
An axis of an array.
list
A single dimension array.
table
A two dimension array.
array member
An element or value in an array.
index
An operator that allows us to reference a member of an array.
offset
The method of referencing array members by starting at zero.
Conditional Compilation
An introduction and example of conditional compilation as used within the
C++ programming language.
Overview
As you proceed in your programming career, the problems/tasks that need
solving become more complex. The documentation of the algorithm done in
pseudo code (or some other method) will still need to be converted into a
programming solution. Inevitably, when writing that source code mistakes
will be introduced. When learning the syntax of a new programming
language, programmers sometimes automatically think in their old language
syntax, and make mistakes that are sometimes hard to detect.
The concept of using a flag to either activate or have remain dormant
certain lines of code designed solely to help with the debugging of a
program has existed since almost the beginning of modern computer
programming (1950's). One of the debugging tools available within C++ is
conditional compilation. For our flag, we would use a defined constant
like:
#define DEBUG 1
Then using another compiler directive pair, the #if and #endif, we can have
the compiler during the pre-processor either include or not include one or
more lines of code.
#1if DEBUG
COU <=" \fie 7 >> “DEBUG Code-7 Ha mom! =.
#endif
Of course saying "Hi mom!" is not very useful for debugging your code.
However, you can use test data with conditional compilation. A series of
input data values and a series of output predictors can be placed in the
program. Then you can turn on the debug feature or turn them off with your
debugging flag.
You should study the demonstration program in conjunction with this
module.
Demonstration Program in C++
Creating a Folder or Sub-Folder for Source Code Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Demo_Programs
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Demo Program
Download and store the following file(s) to your storage device in the
appropriate folder(s). Following the methods of your compiler/IDE,
compile and run the program(s). Study the source code file(s) in
conjunction with other learning materials. You may need to right click on
the link and select "Save Target As" in order to download the file.
Download from Connexions: Demo Conditional Compliation.cpp
Definitions
conditional compilation
A compiler directive that includes or excludes lines of code based on a
Boolean expression.
Practice 23: More Arrays & Compiler Directives
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Have an exposure to multidimensional arrays.
3. Understand conditional compilation as a testing technique.
4. When supplied with test data, add conditional compilation lines to an
existing C++ source code.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Very few arrays need more than one axis.
2. Multidimensional arrays use multiple square brackets, one set per
axis.
3. Using a flag to activate debugging lines of code has been around
since the 1950s.
4, Within C++ we can use the conditional compilation compiler
directives to implement debugging line of code.
Solution:
Answers:
1. false
2. true
3. true
4. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 23 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_23 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_23a.cpp
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
e Compile and run the Lab_23a.cpp source code file. Understand how it
works.
¢ Copy the source code file Lab_23a.cpp naming it: Lab_23b.cpp
e Add conditional compilation statements similar to the demonstration
program used in the Conditional Compilation Connexions module.
Specifically use: 157 pennies, 92 nickels, 23 dimes and 31 quarters as
your test data.
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 23a — Instructions
Give three examples in the real world where data might be structured into a
multidimensional array. One example (and you can’t count it) is a theatre
ticket which might have a section, row and seat number on it.
Object Oriented Programming
An overview of how object oriented programming is different from
procedural or modular structured programming.
Discussion
"In procedural programming, the programmer constructs procedures (or
functions, as they are called in C++). The procedures are collections of
programming statements that perform a specific task. The procedures each
contain their own variables and commonly share variables with other
procedures. Procedural programming is centered on the procedure or
function."[footnote] For decades (1950s to through the 1980s) most
programming was taught as procedural programming. Coupled with the
imposition of using standardized control structures in the late 1960s, we
have what is typically called modular structured programming.
Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++
Early Objects Sixth Edition (United States of America: Pearson — Addison
Wesley, 2008) 22.
Another, equally valid approach to programming is object-oriented
programming or OOP. It was introduced in the mid 1980s and was widely
accepted as a programming approach by the early 1990s. The first
languages to introduce OOP to the masses were C++ and Java. Shortly after
their introduction, there were American National Standards Institute (ANSI)
standards established for those languages. Today, C++ and Java are widely
used.
"The primary differences between the two approaches is their use of data. In
a procedural program, the design centers around the rules or procedures for
processing the data. The procedures, implemented as functions in C++, are
the focus of the design. The data objects are passed to the functions as
parameters. The key question is how the functions will transform the data
they receive for either storage or further processing. Procedural
programming has been the mainstay of computer science since its
beginning and is still heavily used today.
In an object-oriented program, abbreviated OOP, the design centers around
objects that contain (encapsulate) the data and the necessary functions to
process the data. In OOP, the objects own the functions that process the
data."[footnote |
Behrouz A. Forouzan and Richard F. Gilberg, Computer Science A
Structured Approach using C++ Second Edition (United States of America:
Thompson — Brooks/Cole, 2004) 156.
"Object-oriented programming ... is centered on the object. An object is a
programming element that contains data and the procedures that operate on
the data. The objects contain, within themselves, both the information and
the ability to manipulate the information."| footnote]
Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++
Early Objects Sixth Edition (United States of America: Pearson — Addison
Wesley, 2008) 22.
To help complicate the picture, the C++ programming language can be used
(and is used) to write either a procedural program (modular structured
program) or an object-oriented program. Some items used by those writing
procedural programs in C++ are in fact objects. Examples include:
1. Standard input and output items of: cout and cin; example:
cout.setf(ios::fixed)
2. Strings; calculating the length with: identifier_name.length()
3. File input/output; example: inData.open(filespec, ios::in)
Objects are implemented with a "class" data type; which is a complex or
derived data type. Implementation details will not be presented in the
module.
Transition
Many students will learn modular structured programming before learning
object-oriented programming. The common way of teaching programming
fundamentals is to cover them or divide them into three courses, usually
covered in this order:
1. Modular structured
2. Object-oriented
3. Data structures
The following items learned in modular structured programming flow into
the learning of object-oriented programming:
1. The standard and complex data types are the same
2. The operators are the same, thus data manipulation is the same
3. The control structures are the same
4. Concepts of documentation and making code readable are the same
5. The use of test data to verify logical thinking and program results is
similar
Definitions
procedural programming
Aka modular structured programming.
object oriented
A programming approach that encapsulates data with functions.
Understanding High Performance Computing
An explanation of the difference between sequential programming and
parallel programming concepts with examples of each. A historical sketch
of computers with examples of high performance computing solving
problems using parallel programming concepts. Suggestions for various
groups of learners to explore high performance computing. Includes
software programs, source code files and several Internet links.
Preface — November 13, 2009
This module was created as an entry for the 2008-'09 Open Education
Cup: High Performance Computing competition. The competition was
supervised by Dr. Jan Erik Odegard, Executive Director of the Ken
Kennedy Institute for Information Technology at Rice University. It was
submitted to the "Parallel Algorithms and Applications" category and
specifically designed as an introduction to the subject targeting intermediate
grade school students to collegiate undergraduates who have little
knowledge of High Performance Computing (HPC).
This module received the "Best Module" award for the "Parallel
Algorithms and Applications" category which included a US $500 prize.
Those who reviewed the entries for the competition made some suggestions
for improvement and most have been incorporated into this revised edition
of the module. As always; my thanks to them and all others who make
suggestions for improving educational materials.
Kenneth Leroy Busbee
Introduction to High Performance Computing
Grouping multiple computers or multiple computer processors to
accomplish a task quicker is referred to as High Performance Computing
(HPC). We want to explain how this is accomplished using parallel
programming algorithms or concepts.
The Shift from a Single Processor to Parallel
We are going to start our explanation by giving two simple examples.
Example:
After eating all you can, you toss your chicken leg bone out of the car
window (shame on you for trashing up the highway), but in short order an
ant finds your tossed chicken bone. One single ant could bite off the left
over on the bone and transport it to the colony, one bite at a time; but, it
might take him 1 whole day (24 hours) of work. But, what if he gets help?
He signals some buddies and being a small colony of ants they allocate a
total of 10 ants to do the task. Ten times the workers take one tenth the
time. The ten ants do the task in 2 hours and 24 minutes.
I toss another bone out the window. An ant finds it and the colony allocates
50 ants to do the task of picking the bone clean. In less than 30 minutes
(28.8 to be exact) the 50 ants working in parallel complete the task.
Example:
One painter might take 8 hours to paint the exterior of an average sized
house. But, if he can put a crew of 10 painters working simultaneously (or
in other words in parallel) it takes only 48 munities. What about a crew of
50 painters assuming that they can do work and not get in the way of each
other; well how about less than 10 minutes (9.6 to be exact).
Now let's make sure we understand that the same amount of work was done
in the examples given. The work was only completed in a shorter amount of
time because we put more workers on the task. Not all tasks can be divided
up in this way, but when it can be divided between multiple workers, we
can take advantage of the workers doing their sub part of the task in
parallel. Let’s look at another example.
Example:
I want to drive from Houston, Texas to Dallas, Texas; a distance of about
250 miles. For easy calculations let's say I can travel 50 miles in one hour.
It would take me 5 hours. Well, I could divide the task between 5 cars and
have each car travel 50 miles and arrive in Dallas in 1 hour. Right?
Well, wrong. The task of driving from Houston to Dallas cannot be divided
into tasks that can be done in parallel. The task can only be done by one
person driving in a line from Houston to Dallas in 5 hours. I used the word
"line" because it helps connect us to the word: linear. A linear task cannot
be broken-up into smaller tasks to be done in parallel by multiple workers.
Within the computer world, the word associated with linear concept is
sequential processing. I must drive one mile at a time in sequence to get to
Dallas.
Our natural tendency is to share the work that is to work in parallel
whenever it is possible. As a group we can accomplish many tasks that can
be done in parallel in less time.
The Birth of Computers — A "Parallel" to Central Processing Unit
(CPU) Story
"ENIAC, short for Electronic Numerical Integrator And Computer, was the
first general-purpose electronic computer (July 1946). It was the first
Turing-complete, digital computer capable of being reprogrammed to solve
a full range of computing problems. ENIAC had twenty ten-digit signed
accumulators which used ten's complement representation and could
perform 5,000 simple addition or subtraction operations between any of
them and a source (e.g., another accumulator, or a constant transmitter)
every second. It was possible to connect several accumulators to run
simultaneously, so the peak speed of operation was potentially much higher
due to parallel operation." (ENIAC from Wikipedia)
Often not understood by many today, the first computer used base 10
arithmetic in the electronics and was a parallel processing machine by
using several accumulators to improve the speed. However, this did not last
for long. During its construction:
"The First Draft of a Report (commonly shortened to First Draft) on the
EDVAC — Electronic Discrete Variable Automatic Computer was an
incomplete 101 page document written by John von Neumann and
distributed on June 30, 1945 by Herman Goldstine, security officer on the
classified ENIAC project. It contains the first published description of the
logical design of a computer using the stored-program concept, which has
come to be known as the von Neumann architecture." (First Draft of a
Report on the EDVAC from Wikipedia)
"The von Neumann architecture is a design model for a stored-program
digital computer that uses a [central] processing [unit] and a single separate
storage structure to hold both instructions and data. It is named after the
mathematician and early computer scientist John von Neumann. Such
computers implement a universal Turing machine and have a sequential
architecture." (Von Neumann architecture from Wikipedia)
Von Neumann also proposed using a binary (base 2) numbering system for
the electronics. One of the characteristics of the von Neumann architecture
was the trade off of multiple processors using base 10 electronics to a single
central processor using base 2 (or digital) electronics. To compare to our ant
example, the idea was to use one real fast ant versus 10 slow ants. If one
real fast ant can do 1,000 tasks in an hour; it would be more powerful (be
able to do more tasks) than 10 ants doing 10 tasks an hour or the equivalent
of 100 tasks per hour.
The rest is history — most commercially built computers for about the first
forty years (1951 to 1991) followed the von Neumann architecture. The
electronic engineers keep building more reliable and faster electronics.
From vacuum tube, to transistor, to integrated circuit to what we call today
"chip" technology. This transformation made computers break down less
frequently (they were more reliable), physically smaller, needing less
electric power and faster. Personal computers were introduced in the late
1970's and within ten years became more commonly available and used.
One short coming was that most programming efforts were towards
improving the linear (or sequential) way of thinking or solving a problem.
After all, the computer electronic engineers would be making a faster
computer next year. Everyone understood that the computer had only one
central processing unit (CPU). Right?
The Need for Power
Well, wrong. Computer scientists and electronic engineers had been
experimenting with multi-processor computers with parallel programming
since 1946. But it's not until the 1980's that we see the first parallel
processing computers (built by Cray and other computer companies) being
sold as commercial built computers. It's time for another example.
Example:
The circus traveling by train from one city to the next has an elephant that
dies. They decide to toss the elephant off the train (shame on them for
trashing up the country side), but in short order a "super" ant (faster than
most regular ants) finds the elephant. This project is much larger than your
tossed chicken bone. One single "super" ant could do the task (bite off a
piece of the elephant and transport it to the colony, one bite at a time); but,
it might take one whole year. After all this requires a lot more work than a
chicken bone. But, what if he gets help? He signals some buddies and
being a large colony of "super" ants they allocate a total of 2,190 ants to do
the task. Wow, they devour the elephant in six hours.
This elephant example is exactly where the computer scientists had arrived.
The electronic engineers were going to continue to make improvements in
the speed of a single central processing unit computer, but not soon enough
to satisfy the "need for power" to be able to solve tasks requiring immense
computing power. Some of the new tasks that would require immense
computer power included the human genome project, searching for oil and
gas by creating 3 dimensional images of geological formations and the
study of gravitational forces in the universe; just to mention a few. The
solution: parallel processing to the rescue. Basically the only way to get this
immense computer power was to implement parallel processing techniques.
During the late 1970's and early 1980's scientists saw the need to explore
the parallel processing paradigm more fully and thus the birth of High
Performance Computing. Various national and international conferences
started during the 1980's to be able to further the cause of High
Performance Computing. For example in November of 2008 the "SC08"
supercomputing conference celebrated their 20" anniversary.
The predicting of the weather is a good example for the need of High
Performance Computing. Using the fastest central processing unit computer
it might take a year to predict tomorrow's weather. The information would
be correct but 365 days late. Using parallel processing techniques and a
powerful "high performance computer", we might be able to predict
tomorrow’s weather in 6 hours. Not only correct, but in time to be useful.
Measuring Computer Power
Most people are familiar with the giga hertz (billions of instructions per
second) measure to describe how fast a single CPU's processor is running.
Most microcomputers of today are running around 3 GHz or 3 billion
instructions a second. Although 3 billion sounds fast, many of these
instructions are simple operations.
Supercomputing uses a measurement involving floating point arithmetic
calculations as the benchmark for comparing computer power. "In
computing, FLOPS (or flops or flop/s) is an acronym meaning FLoating
point Operations Per Second." and again "On May 25, 2008, an American
military supercomputer built by IBM, named 'Roadrunner', reached the
computing milestone of one petaflop by processing more than 1.026
quadrillion calculations per second." (FLOPS from Wikipedia) For those of
us not familiar:
Example:
Getting a Sense of Power
S billion Of 3° GHZ is:
3,000, 000, 000
1 quadrillion or 1 pedaflop is:
1,000, 000, 000, 000, 000
You also should realize that your personal computer is not doing 3 gigafolp
worth of calculations, but something slower when using the FLOPS
measurement.
High Performance Computing Made Personal
It took several years (about 30) to get computers to a personal level (1951
to 1981). It took about twenty years (late 1980’s to present 2009) to get
multi-processor computers to the personal level. Currently available to the
general public are computers with "duo core" and "quad core" processors.
In the near future, micro computers will have 8 to 16 core processors.
People ask, "Why would I need that much computer power?" There are
dozens of applications, but I can think of a least one item that almost
everyone wants: high quality voice recognition. That's right! I want to talk
to my computer. Toss your mouse, toss your keyboard, no more touch pad —
talk to it.
Again, one short coming is that most programming efforts have been
towards teaching and learning the sequential processing way of thinking or
solving a problem. Educators will now need to teach and programmers will
now need to develop skills in programming using parallel concepts and
algorithms.
Summary
We have bounced you back and forth between sequential and parallel
concepts. We covered our natural tendency to do work in parallel. But with
the birth of computers the parallel concepts were set to the side and the
computer industry implemented a faster single processor approach
(sequential). We explained the limitations of sequential processing and the
need for computing power. Thus, the birth of High Performance
Computing. Parallel processing computers are migrating into our homes.
With that migration, there is a great need to educate the existing generation
and develop the next generation of scientists and programmers to be able to
take advantage of High Performance Computing.
Learner Appropriate Activities
High Performance Computing is impacting how we do everything.
Learning, working, even our relaxation and entertainment are impacted by
HPC. To help more people understand HPC, I have listed appropriate
activities based on where a learner is in relation to their programming skills.
Computer Literacy but No Programming Skills
We have provided two computer programs that help students see the impact
of parallel processing. The first is a "Linear to Parallel Calculator" where
the student enters how long it would take one person to complete a task,
asks how many people will work as a group on the task, then calculates how
long it will take the group to complete the task. The second is a "Parallel
Speed Demonstration Program" that simulates parallel processing. It
displays to the monitor the first 60 factorial numbers in 60 seconds, then
shows as if 10 processors are doing it in 6 seconds, then as if 100
processors are doing it in less than 1 second. Both are compiled and ready
for use on an Intel CPU machine (compiled for use on Windows OS).
Download the executable file from Connexions: Linear to Parallel
Calculator
Download the executable file from Connexions: Parallel Speed
Demonstration Program
An interesting activity would be to join a group that is using thousands of
personal microcomputers via Internet connections for parallel processing.
Several distributed processing projects are listed in the "FLOPS" article on
Widipedia. One such group is the "Great Internet Mersenne Prime Search -
GIMPS".
A link to the GIMPS web site is: http://www.mersenne.org/
Another activity is to "Google" some keywords. Be careful - "Googling"
can be confusing and often can be difficult to focus on the precise subject
that you want.
e high performance computing
¢ computational science
e supercomputing
e distributed processing
Learning Programming Fundamentals
Students learning to program that are currently taking courses in
Modular/Structured programming and/or Object Oriented programming
might want to review the source code files for the demonstration programs
listed above. These programs do not do parallel programming, but the
student could modify or improve them to better explain parallel
programming concepts.
You may need to right click on the link and select "Save Target As" in order
to download these source code files.
Download the source code file from Connexions: Linear to Parallel
Calculator
Download the source code file from Connexions: Parallel Speed
Demonstration Program
Another appropriate activity is to "Google" some of the key words listed
above. With your fundamental understanding of programming, you will
understand more of the materials than those with no programming
experience. You should get a sense that parallel programming is becoming a
more important part of a computer professional’s work and career.
Review the "Top 500 Super Computers" at: http://www.top500.org/
Look at the source code listings provided in the next section, but remember,
you cannot compile or run these on your normal computer.
Upper Division Under-Graduate College Students
The challenge is to try parallel computing, not just talk about it.
During the week of May 21st to May 26th in 2006, this author attended a
workshop on Parallel and Distributed Computing. The workshop was given
by the National Computational Science Institute and introduced parallel
programming using multiple computers (a group of micro computers
grouped or clustered into a super-micro computer). The conference
emphasized several important points related to the computer industry:
1. During the past few years super-micro computers have become more
powerful and more available.
2. Desk top computers are starting to be built with multiple processors (or
cores) and we will have multiple (10 to 30) core processors within a
few years.
3. Use of super-micro computing power is wide spread and growing in all
areas: scientific research, engineering applications, 3D animation for
computer games and education, etc.
4. There is a shortage of educators, scientific researchers, and computer
professionals that know how to manage and utilize this developing
resource. Computer professionals needed include: Technicians that
know how to create and maintain a super-micro computer; and
Programmers that know how to create computer applications that
use parallel programming concepts.
This last item was emphasized to those of you beginning a career in
computer programming that as you progress in your education, you should
be aware of the changing nature of computer programming as a profession.
Within a few years all professional programmers will have to be familiar
with parallel programming.
During the conference this author wrote a program that sorts an array of
150,000 integers using two different approaches. The first way was without
parallel processing. When it was compiled and executed using a single
machine, it took 120.324 seconds to run (2 minutes). The second way was
to redesign the program so parts of it could be run on several processors at
the same time. When it was compiled and executed using 11 machines
within a cluster of micro-computers, it took 20.974 seconds to run. That’s
approximately 6 times faster. Thus, parallel programming will become a
necessity to be able to utilize the multi-processor hardware of the near
future.
A distributed computing environment was set up in a normal computer lab
using a Linix operating system stored on a CD. After booting several
computers with the CD, the computers can communicate with each other
with the support of "Message Passing Interface" or MPI commands. This
model known as the Bootable Cluster CD (BCCD) is available from:
Bootable Cluster CD — University of Northern Iowa at:
http://www.bccd.net/
The source code files used during the above workshop were modified to a
version 8, thus an 8 is in the filename. The non-parallel processing "super"
code was named: nonps8.cpp with the parallel processing "super" code
named: ps8.cpp (Note: The parallel processing code contains some
comments that describe that part of the code being run by a machine
identified as the "SERVER_NODE" with a part of the code being run by
the 10 other machines (the Clients). The client machines communicate
critical information to the server node using "Message Passing Interface" or
MPI commands.)
You may need to right click on the link and select "Save Target As" in order
to download these source code files.
Download the source code file from Connexions: nonps8.cpp
Download the source code file from Connexions: ps8.cpp
Two notable resources with super computer information were provided by
presenters during the workshop:
Oklahoma University — Supercomputing Center for Education & Research
at: http://www.oscer.ou.edu/education.php
Contra Costa College — High Performance Computing at:
http://contracosta.edu/hpc/resources/presentations/
You can also "Google" the topic's key words and spend several days reading
and experimenting with High Performance Computing.
Consider reviewing the "Educator Resources" links provided in the next
section.
Educator Resources
There are many sites that provide materials and assistance to those teaching
the many aspects of High Performance Computing. A few of them are:
Shodor — A National Resource for Computational Science Education at:
http://www.shodor.org/home/
CSERD — Computational Science Education Reference Desk at:
http://www.shodor.org/refdesk/
National Computational Science Institute at:
http://www.computationalscience.org/
Association of Computing Machinery at: http://www.acm.org/
Super Computing — Education at: http://sc09.sc-
education.org/about/index.php
Simple Definitions
high performance computing
Grouping multiple computers or multiple computer processors to
accomplish a task in less time.
sequential processing
Using only one processor and completing the tasks in a sequential
order.
parallel processing
Dividing a task into parts that can utilize more than one processor.
central processing unit
The electronic circuitry that actually executes computer instructions.
parallel programming
Involves developing programs that utilize parallel processing
algorithms that take advantage of multiple processors.
Practice 24: OOP & HPC
Questions, exercises, problems, etc. that support this chapter in the
"Programming Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Learning Objectives
With 100% accuracy during a: memory building activity, exercises, lab
assignment, problems, or timed quiz/exam; the student is expected to:
1. Define the terms on the definitions as listed in the modules associated
with this chapter.
2. Gain an exposure to object-oriented programming.
3. Gain an exposure to high performance computing.
4. G iven general instructions, write the C++ code for a program that
includes a general review of the textbook/collection/course.
Memory Building Activities
Link to: [missing_resource: index.html]
Exercises
Exercise:
Problem:
Answer the following statements as either true or false:
1. Procedural programming and object-oriented programming
cannot be done with the same compiler/IDE.
2. Object-oriented programming encapsulates data and functions.
3. High Performance Computing is a new topic on the computer
scene.
4. The concepts and examples of High Performance Computer are
difficult to explain.
5. All programmers will need to know about parallel programming
in the near future.
Solution:
Answers:
1. false
2. true
3. false
4. false
5. true
Miscellaneous Items
None at this time.
Lab Assignment
Creating a Folder or Sub-Folder for Chapter 24 Files
Depending on your compiler/IDE, you should decide where to download
and store source code files for processing. Prudence dictates that you create
these folders as needed prior to downloading source code files. A suggested
sub-folder for the Bloodshed Dev-C++ 5 compiler/IDE might be named:
e Chapter_24 within the folder named: Cpp_Source_Code_Files
If you have not done so, please create the folder(s) and/or sub-folder(s) as
appropriate.
Download the Lab File(s)
Download and store the following file(s) to your storage device in the
appropriate folder(s). You may need to right click on the link and select
"Save Target As" in order to download the file.
Download from Connexions: Lab_24 Narrative Description.txt
Detailed Lab Instructions
Read and follow the directions below carefully, and perform the steps in the
order listed.
¢ Create a source code file following the directions in the
Lab_24 Narrative_Description.txt file. Name it: Lab_24.cpp
e Build (compile and run) your program.
e After you have successfully written this program, if you are taking this
course for college credit, follow the instructions from your
professor/instructor for submitting it for grading.
Problems
Problem 24a — Instructions
Describe the fundamental differences between procedural (modular
structured) programming and object-oriented programming.
Problem 24b — Instructions
Explain why High Performance Computing is needed to predict tomorrow’s
weather.
Review: Foundation Topics Group: 1-5
Review materials that support a group of chapters in the "Programming
Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Strategy Discussion
Exams vary depending on your instructor. Many will use the following:
1. Definitions
2. Self-grading questions including true/false, multiple choice, short
answer, etc.
3. Problems
The materials in this textbook/collection have covered these items at the
end of every chapter within the Practice module for that chapter. We
suggest the following test preparation strategies:
1. If your professor is testing the definitions and expecting you to have
them memorized, you should review the “Using the Flash Card
Activity” within the “Study Habits that Build the Brain” module
within the Appendix materials. Practice writing your definitions using
the Flash Card Activity in the Memory Building Activities (MBAs)
available within the Practice modules or in the Memory Building
Activities within this Review module.
2. Do a quick review of any exercises within the Connexions modules or
the Practice modules. Also review quizzes or exams that you have
taken and pay special attention to making sure you understand why
you missed a question.
3. If your professor has indicated that they might include a few of the
problems presented within the Practice modules, make sure you have
formulated a good answer for each problem. If authorized, collaborate
with other students to improve your answers to the problems. Spend a
moderate amount of time reviewing each problem with its answer
before the exam.
Memory Building Activities
Link to: [missing_resource: index.html]
Miscellaneous Items
Link to: Manipulation of Data Part 1
Review: Modular Programming Group: 6-9
Review materials that support a group of chapters in the "Programming
Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Strategy Discussion
Exams vary depending on your instructor. Many will use the following:
1. Definitions
2. Self-grading questions including true/false, multiple choice, short
answer, etc.
3. Problems
The materials in this textbook/collection have covered these items at the
end of every chapter within the Practice module for that chapter. We
suggest the following test preparation strategies:
1. If your professor is testing the definitions and expecting you to have
them memorized, you should review the “Using the Flash Card
Activity” within the “Study Habits that Build the Brain” module
within the Appendix materials. Practice writing your definitions using
the Flash Card Activity in conjunction with the Memory Building
Activities (MBAs) available within the Practice modules or in the
Memory Building Activities within this Review module.
2. Do a quick review of any exercises within the Connexions modules or
the Practice modules. Also review quizzes or exams that you have
taken and pay special attention to making sure you understand why
you missed a question.
3. If your professor has indicated that they might include a few of the
problems presented within the Practice modules, make sure you have
formulated a good answer for each problem. If authorized, collaborate
with other students to improve your answers to the problems. Spend a
moderate amount of time reviewing each problem with its answer
before the exam.
Memory Building Activities
Link to: [missing_resource: index.html]
Miscellaneous Items
None at this time.
Review: Structured Programming Group: 10-16
Review materials that support a group of chapters in the "Programming
Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Strategy Discussion
Exams vary depending on your instructor. Many will use the following:
1. Definitions
2. Self-grading questions including true/false, multiple choice, short
answer, etc.
3. Problems
The materials in this textbook/collection have covered these items at the
end of every chapter within the Practice module for that chapter. We
suggest the following test preparation strategies:
1. If your professor is testing the definitions and expecting you to have
them memorized, you should review the "Using the Flash Card
Activity" within the "Study Habits that Build the Brain" module within
the Appendix materials. Practice writing your definitions using the
Flash Card Activity in conjunction with the Memory Building
Activities (MBAs) available within the Practice modules or in the
Memory Building Activities within this Review module.
2. Do a quick review of any exercises within the Connexions modules or
the Practice moudles. Also review quizzes or exams that you have
taken and pay special attention to making sure you understand why
you missed a question.
3. If your professor has indicated that they might include a few of the
problems presented within the Practice modules, make sure you have
formulated a good answer for each problem. If authorized, collaborate
with other students to improve your answers to the problems. Spend a
moderate amount of time reviewing each problem with its answer
before the exam.
Memory Building Activities
Link to: [missing_resource: index.html]
Miscellaneous Items
Link to: Animated gif showing an if then else
Link to: Animated gif showing ado while loop
Link to: Animated gif showing a while loop
Link to: Manipulation of Data Part 2
Link to: Manipulation of Data Part 3
Review: Intermediate Topics Group: 17-21
Review materials that support a group of chapters in the "Programming
Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Strategy Discussion
Exams vary depending on your instructor. Many will use the following:
1. Definitions
2. Self-grading questions including true/false, multiple choice, short
answer, etc.
3. Problems
The materials in this textbook/collection have covered these items at the
end of every chapter within the Practice module for that chapter. We
suggest the following test preparation strategies:
1. If your professor is testing the definitions and expecting you to have
them memorized, you should review the "Using the Flash Card
Activity" within the "Study Habits that Build the Brain" module within
the Appendix materials. Practice writing your definitions using the
Flash Card Activity in conjunction with the Memory Building
Activities (MBAs) available within the Practice modules or in the
Memory Building Activities within this Review module.
2. Do a quick review of any exercises wtihin the Connexions modules or
Practice modules. Also review quizzes or exams that you have taken
and pay special attention to making sure you understand why you
missed a question.
3. If your professor has indicated that they might include a few of the
problems presented within the Practice modules, make sure you have
formulated a good answer for each problem. If authorized, collaborate
with other students to improve your answers to the problems. Spend a
moderate amount of time reviewing each problem with its answer
before the exam.
Memory Building Activities
Link to: [missing_resource: index.html]
Miscellaneous Items
None at this time.
Review: Advanced Topics Group: 22-24
Review materials that support a group of chapters in the "Programming
Fundamentals - A Modular Structured Approach using C++"
collection/textbook.
Strategy Discussion
Exams vary depending on your instructor. Many will use the following:
1. Definitions
2. Self-grading questions including true/false, multiple choice, short
answer, etc.
3. Problems
The materials in this textbook/collection have covered these items at the
end of every chapter within the Practice module for that chapter. We
suggest the following test preparation strategies:
1. If your professor is testing the definitions and expecting you to have
them memorized, you should review the "Using the Flash Card
Activity" within the "Study Habits that Build the Brain" module within
the Appendix materials. Practice writing your definitions using the
Flash Card Activity in conjunction with the Memory Building
Activities (MBAs) available within the Practice modules or in the
Memory Building Activities within this Review module.
2. Do a quick review of any exerecises within the Connexions modules or
the Practice modules. Also review quizzes or exams that you have
taken and pay special attention to making sure you understand why
you missed a question.
3. If your professor has indicated that they might include a few of the
problems presented within the Practice modules, make sure you have
formulated a good answer for each problem. If authorized, collaborate
with other students to improve your answers to the problems. Spend a
moderate amount of time reviewing each problem with its answer
before the exam.
Memory Building Activities
Link to: [missing_resource: index.html]
Miscellaneous Items
None at this time.
Abbreviated Precedence Chart for C++ Operators
An abbreviated precedence chart for C++ operators typically used in a modular structured programming
fundamentals course.
An operator is a language-specific syntactical token (one or more symbols) that causes an action to be taken on
one or more operands. The following item provides an abbreviated list of those C++ operators that are typically
taught in a programming fundamentals course that teaches modular structured programming concepts.
The first column shows the precedence (the higher precedence is 1 or it goes first) and operators that have the
same precedence also have the same associativity (the associativity is only listed once for the group of operators).
Decrement is two minus signs, but some word processing software programs might have problems printing two
minus signs and convert it to a double dash. Insertion (two < signs) and extraction (two > signs) might also have
printing problems. These printing problems are noted in the comments with emphasized text.
OPERATOR
Ee NAME
1 function call
1 index
2 class member
D) postfix
increment
) postfix
decrement
3 indirection
3 address
3 unary
positive
3 unary
negative
3 prefix
increment
3 prefix
decrement
3 cast
3 sizeof
SYMBOL(S)
0
[]
++
++
(type)
sizeof (type)
COMMENTS
aka array
index
a period
unary
unary, two
minus signs
unary, aka
dereference
unary
unary, aka
plus
unary, aka
minus
unary
unary, two
minus signs
unary
unary
ASSOICIATIVITY
Left to Right
Right to Left
Right to Left
CONNEXIONS
MODULE
m19145
12
12
12
12
logical NOT
multiply
divide
modulus
add
subtract
insertion
extraction
less than
greater than
less than or
equal to
greater than
or equal to
equality
inequality
logical AND
logical OR
conditional
assignment
addition
assignment
subtraction
assignment
multiplication
assignment
division
assignment
modulus
assignment
<<
>>
*=
%=
unary
remainder
writing, two
less than
signs
reading, two
greater than
signs
equal to
not equal to
trinary
Left to Right
Left to Right
Left to Right
Left to Right
Left to Right
Left to Right
Left to Right
Left to Right
Right to Left
m19549
m19549
m19549
m19549
m19549
m19549
m19847
m19847
m18743
m18743
m18743
m18743
13
sequence or
comma
Left to Right
C++ Reserved Keywords
A brief explanation and list of C++ reserved keywords for use in a
programming fundamentals course.
All programming languages have "reserved words". There are usually less
than 50 of these reserved words in any given programming language. They
are reserved because they have been pre-assigned a specific meaning within
that programming language, thus the compiler recognizes those words to
mean a specific thing or action. Within C++ the reserved words are also
known as "keywords".
Programmers use identifier names for a variety of items, to include:
functions, variables, named constants, alias names, etc. But, they can't use
as identifier names the words that are "reserved to the language".
For the C++ language all "reserved keywords" are typed in lower case. The
list that follows includes the American National Standards Institute (ANSI)
and the International Organization for Standardization (ISO) lists of
reserved words for the C++ programming language. The ISO reserved
words may not be implemented in the compiler that you are using, however
they may be adopted in future releases of C++ compilers. Wisdom dictates
to avoid using them at this point so that there will not be a problem
compiling your source code in future releases of compilers. There has been
no distinction made in the ANSI or ISO reserved word lists. A search of the
Internet for C++ reserved words will reveal several different lists. Some are
more unique to a specific compiler. Some will be incomplete because the
list has been enlarged. The talbe that follows should work for any beginning
programming course using C++. The reserved keywords are:
and double not_eq throw
and_eq dynamic_cast operator true
asm else or try
auto enum or_eq typedef
bitand explicit private typeid
bitor extern protected typename
bool false public union
break float register unsigned
case fro reinterpret-cast using
catch friend return virtual
char goto short void
class if signed volatile
compl inline sizeof wchar _t
const int Static while
const-cast long static_cast Xor
continue mutable struct xor_eq
default namespace switch
delete new template
do not this
ASCII Character Set
Brief explanation of ASCII character set with web links to more
information and tables.
ASCII stands for American Standard Code for Information Interchange
(pronounced "ask-key"). Computers can only understand numbers, so an
ASCII code is the numerical representation of a character such as 'a' or '@'
or an action of some sort. ASCII was developed a long time ago and now
the non-printing characters are rarely used for their original purpose. The
first 32 values (0 to 31) and the last value (127) are the non-printing
characters.
Several software products can be used to create an ASCII text file.
e Notepad within Windows OS and it uses by default the .txt extension.
¢ Microsoft Word by saving the file as 'text only' and it uses by default
the .txt extension.
e Integrated Development Environment (IDE) compliers for most
programming languages usually save source code as ASCII text files
but they will use an extension that describes the content of the text file.
Example: C++ usually uses .cpp as the extension.
The following web links provide more information and tables listing the
ASCII Character Set:
http://asciiset.com/
http://www.asciitable.com/
http://en. wikipedia.org/wiki/ASCII
Show Hide File Extensions
General instructions on how to show or hide file extensions. Specific
instructions and web page links for Windows XP, Windows Vista and
Windows 7 operating systems.
By default, file extensions for known file types are hidden in Windows
operating systems. However, you can change this setting so that file
extensions are shown for all file types. Being able to see file extensions can
be very helpful for students taking computer courses because those course
instructions often refer to file extensions.
All Windows operating systems navigate you to the “Folder Options”
menu, then have you select the “View” tab. Indeed the box is identical in
Windows XP, Windows Vista and Windows 7.
You can apply the view (such as Details or Icons) that
you are using for this folder to all folders of this type.
Apply to Folders
Advanced settings:
Display file size information in folder tips
|] Display the full path in the title bar (Classic theme only)
. Hidden files and folders
@) Dont show hidden files, folders, or drives
©) Show hidden files, folders, and drives
(¥) Hide empty drives in the Computer folder
iM} Hide extensions for known file types
V) Hide protected operating system files (Recommended)
(| Launch folder windows in a separate process
1] Restore previous folder windows at logon
V] Show drive letters
(¥] Show encrypted or compressed NTFS files in color
Restore Defaults
Po
[0K] [_Cancel_] [Anny |
The check in the box acts like a toggle switch. With a check present, it will
hide known file types. Without the check present, it will show all file types.
Click on the box to make the check appear [hide file extensions] or
disappear [show file extensions] and then select “OK”.
Instructions for navigating to the “Folder Options” for various Windows
operating systems along with an Internet link for additional help are
provided below.
Windows XP
With the Windows Explorer open, slect the “Tools” tab and then “Folder
Options”.
Link for additional help: http://www.fileinfo.net/help/windows-show-
extensions.html or http://dotwhat.net/page/displayextensions/
Windows Vista
Select the “Start” button, then “Control Panel”, then “Appearance and
Personalization” and then “Folder Options”.
Link for additional help: http://windows.microsoft.com/en-us/windows-
vista/Show-or-hide-file-name-extensions
Windows 7
Select the “Start” button, then “Control Panel” and then “Folder Options”.
Link for additional help: http://maximumpcguides.com/windows-7/hide-
file-extensions/
Academic or Scholastic Dishonesty
General discussion of academic dishonesty with emphasis on explaining
collusion in courses that use computers.
Introduction
The relationship between faculty and students has always been one of open
and honest communication. The faculty member carries the responsibility
of presenting course materials via reading assignments, lectures, labs, etc.
The student is to learn and understand these materials. Additionally, the
faculty members employ various methods to assess the student’s mastery of
the course materials. Frequently this is done via quizzes, tests, writing
assignments, the completion of lab materials, etc. Academic dishonesty
(sometimes called “Scholastic Dishonesty”) is the violation of that trust.
Cheating on quizzes and tests as well as plagiarism is usually well
understood by students before arriving at the collegiate level of education.
Most colleges include adequate explanation in their student handbook
explaining well what constitutes cheating on exams and plagiarism.
Academic dishonesty often carries some stiff penalties. Usually, the student
receives the grade of “F” from the professor in the course in which he is
enrolled. The student might be expelled from all of their classes for which
they are currently enrolled (“F” in all of your classes) and expelled from the
institution (may not register for classes in the future). Sounds harsh, but it is
a violation of the bond of trust between the student and the educational
institution.
Collusion
Another category of academic dishonesty is collusion which is the
unauthorized collaboration with another person in preparing written work
(including lab assignments) offered for credit (counting towards your grade
calculation). To better understand collusion, students need to realize that as
part of the learning and evaluation of that learning, many professors use
group projects; a directed or authorized collaboration. Often students are
encouraged to form study groups to help discuss the course materials thus
improving the learning process. These authorized and sometimes directed
activities are not collusion.
The following discussion is to help the student understand collusion
(unauthorized collaboration) with specific reference to courses that use
computers. This is not an all inclusive list, but will cover the common
situations that faculty have encountered over the years. Unless your specific
professor informs you differently, you are to assume that the following
items discussed are collusion.
Type it Yourself
Lab assignments are to be your own personal typing efforts. That is you are
to type them or make the modifications yourself to the files (documents,
spreadsheets, databases, programming source code, etc.) If your course is a
programming subject, you are to run the source code file on your compiler,
making corrections as need to complete the lab assignment. If the directions
for an assignment include starting a new file then don’t use an existing file
and modify it to complete the assignment. Unless specifically authorized
by your professor, students should not complete computerized course
work as a team or group and then share the final completed product.
Students have said that they worked as a team or group and that all
participated and all learned the materials. Don’t try this excuse because
professors don’t buy it. Here is the problem: Part of the learning process is
in you doing it yourself. Example: I ask two students to make me some
pancakes for breakfast; I expect two individually prepared plates of
pancakes (one from each of them) for my breakfast. The professor really
does not want to eat two plates of pancakes (or 50 to 100 plates of
pancakes, depending on how many students they are teaching), but part of
your directed learning activity for the course is to demonstrate that you can
make pancakes (not watch someone else make pancakes or participate as a
group to make pancakes).
Control Access to Your Files
Controlling the files you create (or are directed to modify) means that
others will not have access to copy your work. In other words, don’t share
your files.
Students have said that they shared the file so they the other student could
see how the completed assignment should look. Don’t try this excuse
because professors don’t buy it. Here is the problem: When you share the
file you share your typing efforts (or your original work and your efforts to
create that original work). Back to our pancake example: “I only gave the
other student a plate of completed pancakes, so he could see what the end
product should be.” All the other student does is add some blue berries and
whip cream. If a student makes minor modifications to your work (changes
the spots where his name is at) and turns it in as his work — you will be
included in the charge of academic dishonesty. Unless specifically
authorized by your professor, don’t share any files that you create or
modify with another student — ever, not now and not in the future.
Here are two suggestions for controlling access to your files:
When using a course delivery software product or learning system, such as
BlackBorad Vista, don’t give another person your password. With the
password, they will have access to your submitted assignments including
the files that you created.
Don’t leave your files on a machine where others may have access to them.
If multiple students are using or have access to the same machine (often
happens with students living in the same household — husband/wife,
siblings or roommates) or in an on-campus course where many students will
have access to the machine — store your files on a flash drive. Physically
control who gets access to your flash drive.
Ask for a Clarification of the Collaboration
If you have any question about an activity that might be construed as
unauthorized collaboration, ask your professor. They will provide
clarification and direction to you about the activity.
Students have said that they did not understand or think that it was
unauthorized collaboration. Don’t try this excuse because professors don’t
buy it. Here is the problem: We can’t, and won’t list every minor way in
which students can collude. The burden is for you to ask for any
clarification for the specific course from your professor. Don’t assume
that what another instructor allowed in another course will be allowed by
this professor in this course.
Detecting Academic Dishonesty
Professors weren’t born yesterday. The faculty members of most institutions
have individually years and collectively thousands of years at understanding
academic dishonesty. Cheating on tests, plagiarism and collusion are not
new to us. We share our expertise with each other at detecting academic
dishonesty. Additionally, the years of technical computer experience of
professors who teach using computers in lab settings is often astounding.
Students have said that they did not think they could be detected or that
academic dishonesty could not be proved. Don’t try this approach because
professors believe that they are slightly smarter. Actually, we know that we
are a lot smarter. It amazes us that student don’t realize that professors are a
formidable force. Don’t gamble that you can beat us at the “Academic
Dishonesty Game”. Please don’t take this as a challenge and use it as an
excuse to see if you can be academically dishonest and not get caught. We
are warning you, not challenging you.
Serious Consequences
The consequences will vary from instructor to instructor and from
institution to institution. They range from a simple slap on the hand (don’t
do it again) to complete explusion from the institution (expelled from all of
your courses). Because the bond of trust is broken, many instructors will
simply expel you from the course you are taking. As an example: Within
the BCIS1405 course at Houston Community College, we expelled 8
students (along with giving them the grade of “F”) from Distance
Educations sections during the Spring 2008 term for Academic Dishonesty.
Be ready for what ever the consequences your instructor will deliver if you
are dishonest.
Summary
e The ethics of academic honesty; there is a bond of trust that whatever
the student does in relationship to the evaluation process are their own
work and efforts.
e Collusion is the unauthorized collaboration of students on work
submitted for evaluation.
e First directive: Type if yourself
e Second directive: Don’t share your files
e Seek clarification from your professor if you have any doubt that the
collaborative activity might be considered collusion.
e Professors are very capable at detecting academic dishonesty.
e There are usually consequences to your dishonest behavior.
Successful Learning Skills
Discussion and suggestions on planning your learning efforts to be
successful in college courses. Seven key points are covered including: time
commitment, capacity to concentrate, regular study times, variety and
repetition, interaction with other students, procrastination, and attending
class/taking notes.
Realize the Time Commitment
College computer courses often are listed in the catalog of courses with
both lecture and lab hours. But unlike the natural and biological sciences
(chemistry, physics and biology) that must meet in a specific lab room
designed for those courses, students can usually complete their lab portions
at a variety of locations (the college's computer lab, home, work, public
library, friend's house, etc.).
The normal rule of thumb is 1 to 1.5 hours out of class studying for every
hour in class and for computer courses this normally means both the lecture
and lab hours. Students with learning disabilities or those whose primary
language is not English will want to plan for more study time and should
use a larger ratio. Thus, you should calculate the weekly hours of
commitment needed for a course depending on your circumstances.
Example:
If a student is taking a 4 credit hour computer course that the college
catalog says contains a combination of 6 hours (adding your lecture and lab
hours) during a regular 16 week semester; the weekly classroom and study
time for that course would be 12 to 15 hours a week.
But many students take courses at a faster pace by either taking a course
between semesters in a very concentrated mode, starting a course after the
regular start of a semester or during the summer. To calculate the weekly
study time needed you will need to calculate the total regular semester
instructional time and divide by the number of weeks in the faster pace
delivery. Example:
Our 4 credit hour course is to be taken during a summer term that has 9
weeks of instruction time. The total regular semester time would be 15
times the normal semester commitment (180 to 225 hours). Dividing it by 9
would mean 20 to 25 hours per week.
Understand Your Capacity to Concentrate
You cannot expect to spend long periods of time working on computer
course materials. After 3 to 4 hours of working on course materials, your
ability to learn drops significantly (and for most to near zero). This problem
is compounded by the nature of the material which is cumulative in nature.
This means that you must understand item a before you try to learn item b.
All of the math and sciences courses of study are of this nature.
Plan Regular Study Times
The combination of the time commitment and your ability to concentrate
leads to the conclusion that you cannot cram your study time into a week-
end of concentrated study. You must break up your study time into 3 to 4
hour study periods doing only one study period per day. You must establish
a regular routine for each week. Students taking a regular semester course
on-campus will count their class (lecture and lab) time and plan 2 to 3
additional study periods.
If taking a course via distance education, students need to plan for all of the
course time, thus during a regular semester term, our 4 credit hour course
example would require 3 to 4 study periods with 3 to 4 hours for each study
period per week. If taking the course at faster pace (9 week summer term)
you will need to schedule more study times. This may mean a 3 to 4 hour
study period daily for 6 days a week (with only one day off as a day of
rest).
You need to stay on top of a course to successfully complete it. Pacing
yourself with multiple study times allows for effective learning. Students
who procrastinate until close to an exam and then try cramming through
course materials are rarely "A" students.
Learning Requires Variety and Repetition
Variety comes in many forms and includes lecture, lab assignments,
studying textbooks, multi-media materials, quizzes, writing a research
papers, learning activities such as group discussions, crossword puzzles,
flash cards, etc. This variety actually helps our brain to understand and
build memory. In addition to variety, repetition (exposure over multiple
study periods) is essential for our brains to be able to learn and recall the
course materials. Again, this understanding and recall are essential to
courses that require cumulative learning (you must understand item a before
you can learn item b).
Textbooks and professors break-up course materials into chapters or
learning modules often with learning objectives first and review items at the
end of each unit. Each chapter or module might have any of the above
mentioned items. But doing things and study are different. You can't just
show up to class and listen, you can't just read stuff, you need to study.
Study requires a variety of activities. Ask yourself:
e Do you understand each learning objective?
¢ Can you explain or formulate an answer for each learning objective?
e If you did not understand the reading materials, did you re-read it?
e Do the review items (especially questions).
e Take lecture notes.
¢ Do the lecture notes or handouts give you a better understanding than
the textbook?
e Often the problems or lab assignments are to be studied in conjunction
with and reinforce the study materials. Have you tried to do and
understand the problems or lab assignments?
e Are there any learning activities available and if yes, did you do them.
e Did you consider using 3x5 cards to study definitions and vocabulary?
e Did you review the learning objectives before taking any quizzes?
e If the quizzes are computerized, did you study your quiz results?
e After reviewing quiz results and re-study, did you retake the quiz again
if available?
All of this requires time and effort on your part as the student in any course
(distance education or on-campus). You need several study periods a week
to learn the materials in any course. The purpose of a quiz is for you to self
assess your understanding of the materials. If your learning is not complete,
change or modify your learning habits.
Interact with the Other Students
In a normal classroom students interact with each other. They often form
study groups with other students and meet regularly to help each other
study materials. These interactions in most cases are essential to the
learning process. If your only interaction is by private conversation or
private email with the instructor, you are not fully participating in the
course. For distance education students, most learning systems (such as
Blackboard Vista) provide several tools to create this interaction. They
typically include announcements, discussion list, email and chat tools.
Don't Procrastinate and Don't Get Behind
What should you do if you get behind? Plan regular study periods. The
lack of regular study periods is most likely the reason for why you got
behind. Plan when you will do extra study periods in order to catch up.
Attend Class and Take Notes
Taking lecture notes and being able to review those note later when you are
studying provides variety that is needed to learn material. Just writing the
notes down more actively engages the brain, because you are listening and
writing. But you need to arrange with at least two fellow classmates that
you will all take notes and share notes with each other if absent. In addition
to course materials, other administrative matters are discussed in class (such
as the announcement of exam date change).
If you are taking a distance education course, you need to regularly enter
the learning management system (such as Blackboard Vista) and review the
announcements, discussion list postings and read (and answer if
appropriate) email. Most distance education professors assume that
anything he has communicated via these tools will have been read by the
student within 3 days. In short this means you are responsible for having
read the items and completing any action requested.
Study Habits that Build the Brain
Several PowerPoint presentations on how our study habits effect our
learning. A main presentation with additional presentations on reading the
textbook, taking lecture notes, using 3x5 cards and using flash cards to
study.
Introduction
During the spring of 2008 the author, Kenneth Leroy Busbee, did some
research with students taking a computer programming fundamentals
course to determine if using 3x5 cards would improve student performance
on exams. In short, it did! This was not a surprise, but it became obvious
that most of us (faculty at all levels of education as well as students) have
little understanding of how are brain builds understanding and long term
memory.
Attached are several PowerPoint presentations that have been save in an
Adobe PDF format. Please spend a few minutes reviewing the information
provided. Hopefully it will help students to better learn the subjects they are
studying.
Main Presentation
Link to: Study Habits that Build the Brain
Specific Topics
Link to: Reading the Textbook
Link to: Taking Lecture Notes
Link to: Using 3x5 Cards
Link to: Using the Flash Card Activity
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Open Library
American Libraries
TV News
Understanding 9/11